I live and ski mostly in New England. I always get my skis (Volkl SuperSport Allstars now) professionally tuned and waxed at the beginning of the season. Then, I use Swix F-4 wax (that comes in a small canister - you spread it on the bases with a small sponge, let it dry for a few minutes, and then buff it down with a cloth) about every two times that I ski. This wax definitely improves the gliding of the skis, but I don't think it lasts all that long on the bases because of the high friction of the skis running on the mostly man-made snow in New England. I also run a diamond stone down the edges about every two times that I ski to keep any burrs off the edges and to keep the edges reasonably sharp. This method seems to work reasonably well for a small amount of time and money.