Hi mary, welcome to SMF! What sort of additives are you referring to? You can find tons of recipes on the web. How big a batch are you looking to make? What ingredients do you have on hand or available?
What kind of recipe are you looking for? Have you done some research and figured out what process you would like to try - cold process (CP) melt and pour (M&P) hot process (HP)...?
If you haven't done much research into soap making yet, www.millersoap.com is generally recognised as the best beginners website. It has plenty of information, instructions, recipe's, and just general info on soapmaking.
As for additives, yes the amount that would be used will vary depending on a range of things like what it is, how it will benefit your soap or your skin, how pronounced you want the effect of it to be etc. Again, it is a matter of researching and learning.
Like others have said, learn, research, much, ask a lot of questions. Kathy Miller's site should be required reading for newbies! I have been asked for this recipe several times, so I'll post it here and now, but before you start, please read about the safety issues we all face every time we make soap! :shock: OK, this is a easy recipe and you get all the ingredients at Wal-Mary except lye and scent.
I'm giving this in percentages since you can adjust to whatever size you need to fill your mold.
Give it a good cure time to harden up well. You can take a modest water discount. I'd soap it at a 33% lye solution. You can also use Wal-Mart's brand Pre-Creamed animal fats shortening also. The above recipe is all veggie, but I like using the Pre-Creamed shortening. Use 25% of this instead of the Crisco. It will be a firmer bar, too. 8)
I am doing cold process, any amount is fine considerably enough for 58 oz. mold, Any recipe. I need to know how much lye, water, and the amount of additives (When I say adivite I mean goats mile, oatmel.)