I sealed my driveway a while back and learned a couple of things...
try not to seal it on a bright hot day...the sealer dries too fast and if you're not quick enough, you can end up with streaks from one section drying faster that the other. This happens if you put a 2nd coat in only some spots too..
if you use a squeegee...buy one of the better ones. i used a cheapo and it was more of a pain in the arse than what it was worth.
try to move in one general direction. lastly, i think i read in "this old house" magazine about a sealer that contains a non-slip material...try them on-line.
Good luck....my new house has a cement driveway
Jim