i think i asked a similar question to greg on the blog a few wks back. essentially, as the weight got anything above the my 80%, i would have a tendancy to power snatch. (more of an issue for me with the snatch, than the clean)
he suggested to grease the groove by doing tall snatches prior to each snatch. definitely helped. i actually did tall snatches, then high hang snatches (once the weight got too heavy for tall only) before every full snatch rep. once i got to 90%, i would just snatch.
on another note, i actually found the bulgarian cycle was quite helpful for this, in terms on getting very used to getting under a heavy load (80-90% 1rm)... frequently.