I wash my face with soap and water pre-shave (if i haven't just stepped out of the shower) and i think it helps a little. FWIW, i try to use a natural soap if possible - currently using some Johnsons Baby Honey soap my wife gave me a bar of , which seems good.
More important, i believe, is to put plenty of water on your face just before lathering up, as i find otherwise the later can hit a dry, or drying, face and the water gets drained out of it a little, leaving it a little concentrated and draggy.
The thing i have come to learn, for me anyway, is that my facial skin can "drink" quite a lot of water - i find quite a difference post-shave if i wet my face and chin every ten minutes or so - it really helps settle everything down much quicker