Use hot glue, it will stay together nearly forever, then if you mess up, you dont need to waste a whole piece of transparent plastic, you can just pull apart, get you finger nail into the hot glue, and rip it off with no damage done
Drop $10 on this stuff - comes out to about 31 cents an ounce, and an ounce will probably be enough to knock out a helmet.
Like NullARC suggested, it's probably the best stuff to work with. I had used hot glue previously, but this stuff is a lot easier to work with than hot glue.
It's thinner, so your folds and tabs will meet up better. With hot glue, I had a tendency to sort of glob it on, and it could really mess up the model.
It's not hot, so you don't burn your fingers, even a little.
Clean up is a lot easier, use a little water. I always hated those little strands that the hot glue would leave behind.
Super Glue is really expensive in comparison - a .71oz container can cost more than $5!