I don't have a good space to put together a bed sized quilt sandwich. I have used my living room floor, but still have a problem getting all 3 layers smooth without any wrinkles. I finally found a way that seems to work for me. I have an oversized kitchen counter space, 47" x 78". by putting my ironing board at one end I extended that about another 12 inches making it about 47" x 90" of work space. Then I put down the backing and batting ,working with only half, smoothed it out then basted that half. Then I added the other half. I found I could smooth it out easier working with only half at a time. I added the top in the same manner, half at a time. I got the whole large sized quilt smoothed out without any wrinkles. Now I'll have to see if it works as easily the next one I do. :P
What a great tip!