They are so cute, but if you're going to stick them on your project, you don't want to either lose their transparency or have any adhesive show through. That's where the Best Glue Ever comes in. All you need is a tiny drop on the back of each piece. I use my finger to smooth it out over the entire embellishment.
That's basically all you need. It dries tacky and completely transparent, as you can tell by the lighter blue and green stars below.
I used these stars with the Best Glue Ever all over this page. It's my go-to adhesive.