Paul Harm has a lot of good info here.

I would add the Ted Cash oval shaped capper is really nice, you just fill it about 1/2 to 2/3 full, jiggle it a little bit and all but about one cap will right themselves into the correct orientation, then close it and be sure it is fully latched. The in-line capper that I had before (not a Ted Cash) was not playing on my team.