Attaching Stuff to Quilts, and Vice Versa

Do you put unusual stuff on your quilts? I've been embellishing in earnest lately. A few weeks ago, I wrote about stripping this 8" x 8" quilt from scraps. The key and the hawk charm came with holes, making stitching easy. The yellow fish, from a vintage necklace, had a broken hole, so I glued a brooch finding to his back (he can be unpinned from the quilt and worn, a bonus!)

I wanted to put two polished rocks, a piece of beach glass, and a tiny shell to the lower pebble stripe.

How to attach rocks, shells, and beach glass? I'm not good with a drill (it's an aspiration, tips welcomed). So I decided to glue 'eye pins' - lengths of wire with a loop at one end, intended for jewelry making - to the back of the stones and the shell:

Wow, that looks like a tooth, but it's the shell. It's held on by Liquid Fusion Glue, which is strong and dries clear (but shiny, beware). (BTW, I do see now that I need a new cutting mat.)

I left the glue to dry for a day or so, and then used a large safety pin to put holes in the quilt where I wanted the rocks and shell. Cut the non-looped end of the wire to about 2", stuck it through the holes to the back, then, on the back side, with a wire pliers or by hand, swirled the wire around in a circle and flattened.

Here's how the back looked:

Not pretty, but don't worry, because I then stitched the 8" x 8" quilt to the center of a 14" x 14" hemmed piece of coordinating fabric, and wrapped it to the back of a stretched canvas. 

I think I'm going to take out the thumbtacks and use a staple gun instead. 

How do you attach stuff like rocks to quilts? Or quilts to stuff?