I lay them on their side. brake the bead down only on the top. You can fill the tire this way and it's quick. You can blow the tire back up on it's side usually. If you have a problem getting the tire back up to seal the bead, I use a load strap wrapped around the tire to mash tire a little. Stand the tire up with the valve stem at the top, remove valve core and see if any fluid comes out, if it does, thats ok, you only want to fill to the top of the rim.
Hope this helps.