I use T pins to hold the backing to the carpet, taunt but not streached. Then smooth the batting from the middle out, the the same with the top.then pin with 1" curved pins. Crawling around the floor is getting harder though. I have my DD's close all the pins. I haven't had any problems doing it this way. Be sure to use plenty of pins. I use a grid to place my pins, spaced no more than 4" apart. I tryed the spray, and didn't like it. The can said not to use it indoors, and it was very messy.