The same as others are saying, 'high loft polyester batting and less quilting'. Cotton and cotton/poly blend will not give you a soft, fluffy look, especially if there is lots of quilting. Use a high loft polyester, it is sometimes hard to find a high loft and if you can't find high loft layer 2 thinner ones. Also, if you tie rather than quilt it gives the batting more room to expand. But some people don't like to tie, in that case use the least amount of quilting recomended for that batting.
Longarm