I have been getting the Coppola treatment done every 2-3 months for over a year now...(I JUST had it done again today)...to answer your questions...
1. I tip 20%..the process is expensive but it is someone's time and it is also not an easy process to do...they have to blow your hair out straight with the product in it, then flat iron it (NOT easy)
2. You will need sulfate free shampoo (my salon gives me a bottle every time I get the process done)...I use any conditioner I choose though...(I only use salon conditioners though)
3. You do have to wait 3 days...part of the fee is going back for a blow out...I did it the first couple of times, but I actually prefer the way I blow out my hair, so now I skip that and do it myself...
4. You can not put ANYTHING in your hair for the 3 days...not even sunglasses on your head! I use a shower cap in the shower, but I do pull my hair back to wash my face and brush my teeth (that only takes about 3 minutes)...the minute I get up in the morning, I blow out the bed head and flat iron it to seal it back...don't wet your hair or use any product in it for the 3 days
ENJOY! This is a life changing treatment - I can't say enough wonderful things about it!