I've made quite a few with no batting, simply because I'm not a fan of the quilting part of making quilts.
For some I used fleece and some I used flannel for the other side. I sewed them together inside-out like you would a pillow case. I then turned them right side out, hand-sewed the opening, and edge-stitched twice, about 1/4" then about 3/4" from the edge. For some I also tied and some I did not, but both have been washed countless times and have held up well.
Easy-peasy.