I built up to 38 kg snatches with dbs earlier this year. I'm a kitten with my kbs though. The 25kg sucks the life out of me (and normally smashes into the ceiling if I don't train outside).
Something I've mentioned before on here is an idea I got from Ross Enamait:
DB Press 1 rep
DB Push Press 1 rep
DB Snatch 1 rep
Obviously you can build on that with overhead lunges etc. I do that a lot particularly at my parent's house were I have 'nothing' but a 22kg db, a tractor tire, a keg full of water and a lot of land to play with.