Crease along the dashed lines with the blunt end of a pair of scissors. By taking the time to crease the dashed lines, you will have a much easier time folding the glue tabs over. Use very little glue. The biggest problem I have is getting kids to use less glue on each tab. Have your students bring toddler-size shoe boxes to carry their colored pencils, scissors and glue to class every day.
Unfinished models can go in the box at the end of the period.
Ask to switch budgets with the athletic department. Then have your students glue their paper to an old file folder or the cover of a magazine. This will help stiffen up the model. There is no way my students can make these models themselves. Go to your local copy store and enlarge the models onto poster board.