I usually do the entire piece, however I put it on very thinly - I think most folks apply too heavily. Yes, you should see a difference immediately, its usually quite noticeable after a treatment.

The Softener is the most expensive component in the kit. I have the bottles alone for $ 32.99 as that is usually used up the quickest. Again, don't apply too heavily. It's the key component though, and you always want to clean it before applying it. I can do about (25) pieces out of one kit, a mix of sofas / chairs / barstools, etc.