Here is what I have been accustomed to as an acclimation routine and haven't had any acclimated losses thus far:
1. When coming from LFS keep fish in a dark bag so the fish does't get shocked off the bat and don't be tempted to take bag out to say hi to the new fella.
2. Fold brim of bag and let float in water for temp regulation and view of new surroundings for 15 min.
3. After that 15min... with a shot glass take about 25% of the lfs water out and put 25% of mine.
4. After that 15 min add more of my water in.
5.Affter that waiting period the fish can now be taken out of the bag and put in.

Opinions por favor......

for the most part yes, thats how it goes. the thing people dont know is that time is a factor in this proccess. Fish, inverts, and corals all have different time spans for accimating.

fish - 1-3 hours (depending on the fish)
inverts - 4-5
corals - 5-6