I made my brother one. I used a wide piece of fabric, one for top and one for bottom. Then I put in an extra high-loft poly batt. I have a longarm, and even with it, I had to raise my foot a tad to quilt it. But when quilting, I just made huge lines over the quilt, similar to the curvy lines you see on store-bought ones, so it didn't smash the batting flat. It was really easy. The quilting itself was the only challenging part.
My brother loves quilts, especially the soft quilting fabric, but wants them to be fluffy like a comforter, rather than flater. So that was the goal.
Hope this helps!
Debbie in Austin