I noticed a comment regarding Rob's closure on his quilt and thought I would share what I have done.
By lacing 1/16" shockcord through loops at each edge I can adjust closure, but more importantly, I can easily eliminate all gaps along the "back side".
Imagine lying on your right side and trying to tuck in the quilt behind your butt. With this system all I have to do is Push Away the edge I am facing, which will Pull the back edge of the quilt under my thighs, butt, and lower back. Then I pull the facing edge back for a snug front. It is amazingly fast and effective.
In this photo I have added "Draft Tubes" to tighten things up even more. They are "ahead" of the edges and naturally fill the gaps as things close up. Edit: They run from my mid-back to below my butt.
I can say, after many nights on the trail, I am draft free in my quilts, no matter how much rolling around I do.