My kids needed to build gliders for a school design project. Basically, it was indoor, longest glide. So, we quickly hashed a couple up and my son glued up his first ever built up wing. After the project, we later repurposed the bigger glider for towing, and we all enjoyed launching it (see above). 
Here are the gliders. The larger is 24" span and the smaller is 15" (5 panels of 1/16"x3"x3"). It had a 1/8" balsa pod and a bamboo skewer boom. As you can probably guess, the larger one is inspired by John Barker's Lulu classic but with a balsa pod and carbon tube boom.
The uncovered wing came out at 6.3g, which is not bad!
Details of the wing brace. Central spar is 1/16" hard balsa and the brace is a hard wood veneer. 
The "plan" was simply 2cm sq paper. He did a great job of gluing it all up. We used evo stick waterproof glue. Alas, the smaller glider was broken in class - but at least that was after it had won its competition! The larger one was not launched correctly by the teaching assistant so was unable to display its performance. Next, we'll try it on a bungee! 