I always glue flesh side to flesh side as I think the bond is better. As stated, a laminated belt can get awfully thick, more than needed. The liner can also wrinkle if too thick. The problem is, a single layer of leather is somethings too thin. One solution is the bullet loops. If you use the in/out method it tends to stiffen the belt so you can get away with a single layer. This in and out- there are two ways , a loop through one hole or snake the loop leather in and out each hole. The spacing on the holes can be narrowed so you have the loops close together.
When I glue/laminate, I always run stitching around the edges of the belt. I use barge cement from ACE hardware.