WEIGHTS AND MEASURES
Creating scents and beauty recipes is similar to baking and requires measuring and recording the proportion of ingredients you are using. This is particularly important when blending essential oils and incorporating them in your final recipe, as small variations can have an effect on the smell and the safety of your product.
|20-25 drops of essential oil||1ml (this can vary slightly depending on the oil and the brand you are using)|
If you can, try to secure good measuring accessories (digital scale with a tenth of a gram precision, pipettes, etc.). See the Tools & Accessories blog for more info on that.
Source: The Nature of Things