I always wear waterproof, and I also layer. I prefer Maybelline Lash Discovery WP (tiny brush), and usually layer over it either Maybelline Full n Soft WP or Loreal Voluminous WP. I've been testing out the Better than Sex WP from Too Faced but that can't go on its own--it has to go over the Lash Discovery or it's a disaster. I also use a metal lash comb to make sure I have no clumps (I have a whole production...) and I always curl my lashes before I start--WP not only holds a curl better for me, but my eyes water horribly bec of allergies, and this is the only way it won't end up everywhere.
I also never wear it on the lower lashes.