This can be a real tough achievements to get, if you dont play it right. I got busted when i got 98 butterflies. Here are some tipps
1) get the overall picture first.Where is which butterfly and which colour has this one
2) estimate your moves in advance. How many steps you can take until you got this particulare butterfly (DONT, i REPEAT DONT ever feel safe, cause those butterflies have a tendency to get killed pretty fast
3) kill the bottom row at all costs. Whenever you got the chance of clearing the lower parts of the stones with a big bang, DO IT without hesitation. Chance might be that some butterflies which have been considered dead for good, got a second chance of life by falling down some rows.
Update from Daddyfatchops: if you have a butterfly close to the top with no definite match to get rid of it, make matches underneath it, as this will make the butterfly not move up a space. if you make a horizontal match it will stay in the same spot for one more move, and a vertical match underneath it will drop it down 2 spots, buying you some more time.