Ideally you should get one that can measure in 0.1 gram increments like I have because it is very accurate
If you're into ounces, teaspoons and cups, you'll have to learn grams because imperial units simply aren't accurate enough and converting tiny quantities to ounces is VERY messy, e.g. 0.2g = 0.00705oz! I doubt any scale that uses ounces will show that many decimal points! If you find one, great!
If your scale only goes up in 1g increments and you don't want to get another one then you have 2 choices:
1. Make a larger batch
Essential oils cannot be used at a higher concentration that 2%. This means if you are making a 100g batch as I do in my recipes you can only have 1 or 2 grams. I like to split that into several essential oils that's why I end up with 0.2g of this and 0.3g of that. In fact, I would have liked a scale that goes up in 0.01 gram increments then I could have 0.25g of this and 0.75g of that but they are too expensive.
Anyway, if you make a whole litre then 0.2g becomes 2g. But if you don't want make that large a batch then there is another option...
2. Just use one or two essential oils.
If my essential oils add up to 1g then choose your favourite essential oil and just use that. If my essential oils add up to 2g then you can have 1g each of two essential oils.
If you want very accurate scales then you need lab scales not kitchen scales. Examples from amazon are listed to the left/below.