If you go to designer nails website www.designernails.co.uk
they have an NVQ section. There is all the information you need about how to do a rebalance.
I must say I found it incredibly hard and daunting at first because even the creative 4-day foundation didn't really cover rebalancing that well.
The above link tells you what you are aiming for - my first rebalances were full of lifting etc and so it seemed a million miles away from the guidelines for a problem free rebalance.
I found the key is to apply the enhancements well to start with so that there is NO LIFTING in the first place! -
If you do get lifting NEVER nip it away as this can lift layers of the natural nail away as well and causes shattering throughout the rest of the product. The Geek has written a good article on this (go to site stuff, articles). You need instead to be patient and file gently just BEFORE the lifted area. The thicker the enhancement the longer this takes - so again, trick is to apply thinner.
It is frustrating but you will get there promise! - have a good trawl through this site. Good luck!