E6000 is another great adhesive and no burns.

And if you’re sequining all the sequins, these lil bubs are really handy

Zip ties are generally one size fits all. How young of a boy are we talking about?

Also, making this is about as easy of a craft project as there is. You need probably 100 stones, some E-6000, and a wax tipped application tool. You put a small dot of glue on, then push the stone on, and repeat until finished. Don't worry too much if it looks a little funny close up, it'll look great on the dance floor under the lights.