DentonDoc wrote on May 24^th, 2010 at 3:43pm:

If you decide to make your own ground cloth to put under your tent, make sure you cut it SMALLER than the bottom of the tent.  You don't' want water that drips off the tent to drop on the cloth and run UNDER your tent. I'd highly recommend you seam seal even a new tent.

i second these. we always freshen up the seam sealer before we head out on our trips because if you do draw bad weather, nothing is worse than a wet tent. we also take our paddles and lay them over the corners where the rain fly attaches to the tent rings on the ground. that corner on our tent (eureka tetragon 7) sticks out just a tiny bit beyond the fly so this helps.