Also, Anna, keep really good notes. People kept telling me this, and I tried to do it, but ended up with bits of paper all over the place, no idea of what went with what, and then when the soap was finally cured, I couldn't figure out how I'd made the ones I liked and the ones I didn't as much.
I ended up donating almost all of the batches from my first three months to a local shelter - about 40 batches, I think, although I kept a few soaps just for the heck of it - and pretty much only saved the batches after that point. This time with super note-taking (I use Evernote and cut/paste the recipe from soap calc into it, include all additives and amounts, colorants, FO, type of swirl, etc.), attach a picture, and and print out a copy which I keep with its matching batch.
It sounds like a pain, but it really isn't, and you will be so glad that you did it. It is kind of fun to go back and look at them as they start to add up, and it makes it really easy to tinker.