very nice dark Eldar you have here! I really like the metals (especially the gold) and the highlighting on the armour.
For the snow to look more like snow paint the surface you want to cover white. Then cover with a mix of pva and GW snow. Finally when that mix dries apply some pva and sprinkle GW snow on top. It should make your GW snow look more like proper snow
I would also paint the skin in a more light tone. Looking at the skin of your DE now it seems like the armour and skin blend instead of contrasting. Also consider using more red on your models. It would make a huge difference!
Finally consider scraping the idea of using snow bases. You are painting your models in mainly cold colours if you go for a cold themed base the models wont stand out from their bases!
I hope I didnt sound too harsh. Overall I have to say that I really like your painting. My only objection is with your complementing colour choices.