Humblebee & Me‘s tenth birthday was last week, and it’s got me thinking about all the things I’ve learned about making and formulating since I started making things over a decade ago. Today I thought I’d look at eight of the most common mistakes beginners make—mistakes I made, and mistakes I hear about from Bees around the world—and share resources and tips to help you avoid them 😊
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Post Overview
Buying (and using) all the ingredients
It is super tempting to buy all kinds of exciting-sounding ingredients; when I first got started my primary skincare concern was acne, so I bought pretty much any ingredient that mentioned anti-acne benefits. I then proceeded to try to put as many of those ingredients as possible into one or two formulations that I figured would be anti-acne miracle products given the high concentration of ingredients that were supposed to help with acne. Spoiler alert: they were not miracles.
A far better (though definitely more boring) approach is starting with a solid set of basic, functional ingredients. Learn what those ingredients do, how to work with them, and what they’re for. Then, slowly add more ingredients that interest you, researching and experimenting as you go. Knowing why you are using each ingredient and what each ingredient is doing in a formulation will make you a much better formulator, much faster.
If you’re wondering where to start your ingredient shopping, I recently shared a two-part 10-ingredient shopping list for new formulators: Ten DIY Ingredients for Beginner Formulators: Part 1 and Ten DIY Ingredients for Beginner Formulators: Part 2.
And, to help level up your ingredient research skills, definitely give these posts a read: How to Research Your Ingredients: Part 1 and How to Research Your Ingredients: Part 2.
Not working in weights (and percentages)
If you don’t have a scale, it’s really easy to start your making journey using tablespoons and drops to measure your ingredients rather than working in weights. Unfortunately, this is really inaccurate, and it’s impossible to work in percentages (which are super important) if you’re working with volume measurements.
Why is working in percentages super important? Because percentages are universal and relative.
“Percentages (by weight!) are a universal language. Once you start to think and formulate in percentages you will be able to instantly understand so much about formulas—not only yours, but ones you find online, in reference books, and from suppliers and manufacturers. Working in percentages is the first step to understanding how different types of formulas are structured.” (Read more here!)
Learn more about how to use spreadsheets to do all the math work for percentages, scaling, and more with these posts and their partner videos:

This is one of the first body butters I ever made. It’s a 120g batch and I never finished it 🙁
Making huge batches
It can take a while to get a handle on how much of a formulation is enough to get a feel for it you like it or not—especially if you’re coming from cooking or baking, where making a cubic litre of something isn’t all that much.
Here are some of my rules of thumb when I’m making something for the first time:
- Lip balm: 10g–25g (roughly 2–5 tubes) is plenty
- Facial oils: 15g (approx. 0.5 oz)
- Salves, body balms, body butters, and other anhydrous body products: 30–50g (approx. 1–1.76 oz)
- Lotion: 50–100g, depending on how expensive the ingredients are (approx. 1.76–3.5 oz)
- Face wash: 30–50g (1–1.76 oz)
- Hand & body wash: 100g (3.5oz)
- Syndet products: 50g (1.76oz)
I always present my formulations in reasonable amounts, so if you’re looking at something I’ve shared and wondering why the amounts seem tiny, it’s because a little goes a long way!
Read this: How can I weigh out 0.46 grams (and other similarly small/precise amounts)?
Not understanding and following usage rates
Have you ever purchased an ingredient and wondered “how much of this am I supposed to use for it to work?”. That’s where the recommended usage rate for that ingredient comes in!
A massive part of using ingredients safely and effectively is using them within their recommended usage rate. This is information your supplier should provide, and it’s also information I include in the Humblebee & Me DIY Encyclopedia.
Recommended usage rates and maximum allowable usage rates aren’t always the same. For instance, New Directions Aromatics recommends using shea butter at 1–10% in hair conditioner formulations, but there’s no safety reason why you couldn’t use more if that works for your formulation. They recommend using Sodium Cocoyl Isethionate (SCI) at 3–40% in cleanser formulations—which is a very sensible amount of Sodium Cocoyl Isethionate (SCI) to use in many types of cleansing formulations—but the maximum allowable concentration is 49.87% for rinse-off applications.
Out of all the ingredients we work with, I think essential oils are probably the category that sees the most over-use. There’s a lot of incorrect and overly broad information out there about formulating with essential oils, much of it coming with a side helping of “essential oils are safe because they’re natural”. Essential oils are complex, diverse chemicals, and every essential oil has a different chemical composition. Some of the chemicals that comprise essential oils can dangerous (everything from irritating to seriously poisonous), so their use is limited. I learned about how to safely use essential oils in my Formula Botanica Diploma in Organic Skincare Formulation. The Tisserand Institute also provides quality essential oil education, and the book Essential Oil Safety: A Guide for Health Care Professionals by Robert Tisserand & Rodney Young is a fantastic resource.
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Not understanding when a preservative is likely required
Some new makers believe every formulation requires a preservative while some believe none do. The general rule of thumb is that if a formulation contains water and is not designed for immediate consumption or if an otherwise anhydrous formulation might be contaminated with water throughout its lifetime, you probably need a preservative. This is a very broad rule of thumb, but it’s a good place to start.
Some examples:
- Lotions: emulsified lotions require preservatives because they contain water.
- A clay face mask that contains water but is being used up immediately: because it isn’t being stored, it doesn’t need a preservative.
- Bath bombs that are made with water that evaporates off: while the bath bomb is definitely “contaminated” with water during use, it is used up straight away, so no preservative is needed.
- Scrubs: if you portion off single-use amounts you don’t need to add a preservative, but if you plan on storing the whole batch in the bath (or gifting it to somebody who might), a preservative is a good idea as the product is likely to be contaminated with water.
- Bar soap: even though it contains water, the high pH and high anionic surfactant content mean it is self-preserving.
Further reading:
- Preservatives + Shelf Life in the Humblebee & Me FAQ
- Some common myths & misconceptions about preservatives
- Do I need to add a preservative to this recipe? How long will it last?
- What preservative should I use? How much of it should I add?
- Do I need to add a preservative to this if I plan on keeping it in the fridge?
- How do I know my preservative is working?
- Preserving Botanical Formulations Naturally – Part 1 from Botanical Formulations
- Preserving Botanical Formulations Naturally – Part 2 from Botanical Formulations

Some products from the very short-lived Humblebee Beauty & Skin. Selling isn’t for everyone!
Jumping straight into selling
Selling your creations to the public is a big deal; it’s a lot of extra work and bureaucracy above and beyond formulating and making the products. Precisely how much paperwork is required will depend a lot on where you are planning to sell your products, but you will need to tackle challenges like insurance, legally compliant packaging, inventory management, shipping, customer service, and more.
If you’re a new maker, I really really encourage you to wait for a few years before you start selling to the public (especially if you aren’t taking a course to speed up your learning). You wouldn’t open up a restaurant a month after learning how to make toast—similarly, you shouldn’t start selling skincare a month after you make your first lip balm.
I’ve written a longer post on some of the things to consider if you want to sell to the public. If you find the post discouraging that probably just means you need some more time to hone your craft 😊 “If you haven’t talked yourself out of selling stuff at least once, you haven’t done enough research into regulations, liabilities, and all the ‘what ifs’.”
Read this: So, You Want to Sell the Things You Make
Looking for one answer to questions that are giant “it depends” situations
If you’re researching a question and you cannot find anything even vaguely resembling a suitable answer, it may be because the question you’re asking is really big and doesn’t have just one answer.
As a formulator, you have to get used to “it depends” as the answer to many questions. Questions like “What is the best preservative?”, “How much essential oil can I use?”, and so many more do not have one answer. It’s a great big mess of “it depends”.
Watch this: How to find answers to unanswerable questions

Failed lipsticks. I learned things!
Being too afraid to fail—try it and see what happens!
Wondering what will happen if you swap one carrier oil for another, or add X ingredient to a formulation that doesn’t call for it? Try it! Start small, make sure you’re following usage rates, and take lots of notes. Try it and see—it’s a wonderful way to learn.
Watch this: Just try it! You never know what you’ll learn.
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Did I forget a mistake you think new formulators need to know about? Let me know in the comments!
Hi Marie!! This is a REALLY great article and certainly spot on! I have made most of these mistakes myself…only wish I had read this when I started out!!! Thank you for all that you share and your plethora of knowledge!! As a newbie, I’ve learned finding reliable resources is not only key, but imperative! Thank you for being so awesome and sharing such wonderful, insightful information!! Cheers!
Nan
I’m so glad you enjoyed it, Nan! Thanks for DIYing with me, and happy making 🙂
Hi Marie,
Not labelling stuff and not keeping notes of your formulations come to mind…mistakes I still make every now and then (very recently I must admit). So annoying when you make something you absolutely aced and find out you didn’t write it down.
7 years into diy-ing now and still learning and absolutely loving it.
Greetings from Utrecht,
Rose-Anne.
Oh gosh, YES! I cannot believe how many times I’ve found a mystery jar of… something… and the only thing I can remember about it is that I told myself “you’ll remember, no need to label this”. Argh!
This is an incredibly useful post for beginners! Thanks so much and lots of love
I’m so glad you enjoyed it! Thanks for reading 🙂
Been there, done all of these… still a long way to go, but I feel much more confident after +5 years of trial and error! Your site has been a great inspiration and resource <3 Thanks Marie!
Thank you so much, Macarena! ❤️
Buying all the things! I don’t know how many times I’ve bought stuff and have never used it. Or forgot I had it. Or bought it twice because “hey, I’m running low” and then forgot I already bought it. Anyone need any stearic acid? I have lots…. The amount of essential oil bottles I’ve thrown away because it smelled gross or I was allergic to it, but I wanted to try it so I bought it. And don’t get me started on all the people who keep encouraging me to sell the stuff I make. I do this for a fun hobby but have no desire to turn it into a business. Learning all the cosmetic business legalities doesn’t sound like fun at all!
Hi Marie!
I wish I know your website sooner then I don’t have to be struggling with 20 lips balm (recipes from a Chinese influencer on youtube).
These mistakes are related to everyone who just starts with formulations. Even though I practice for 1 year, I am still afraid of failure every time work on new lipstick and blush colors.
Your site is a great hub for DIY lovers! Keep up Marie!
Many thanks from Vietnam