Congratulations! SO much easier than pin basting. I've tried over and over and just can't get both sides smooth with pin basting...probably operator error, as many do use that method.
I smooth with an old 24" ruler that was losing its markings. I lay the batting down first, then lay the backing on (straighten & smooth) and then pull half back & spray directly on the batting...flip and repeat with the top. I do mark centers on the top/bottom to assure the top & bottom are lined up.
We usually lay down a big plastic painters sheet, which I re-use, that way the batting doesn't stick to it. Do be careful with overspray, it is not easy to clean up, even on tile, and beware of anything acrylic (like nails, ask me how I know). It is almost impossible to get off of acrylic nails without a solvent.