Here is a list of ways to attach vellum and transparencies. I cannot take credit for it. I got this from a friend on another MB!
1. Spray adhesives
3. Photo corners
4. Decorative tape (just put it right on there or fold it over the edge of your layout).
5. Decorative attachments (the sample is staples from the EK Success Fastenater).
6. Stickers (use them just like tape to hold the transparency in place).
9. Hide the adhesive - if you lay 1 photo or 1 embellishment on top of your transparency, it gives you a perfect place to hide your adhesive. Just use adhesive where the photo or embellishment will be covering it up (hope that makes sense).
10. Stitching (I love making just a couple of little "X" patterns with a needle and doubled up thread.)
11. Buttons (stitch them in place to adhere the transparency or use a couple to hide your adhesive).
13. Clips (these are Rob & Bob clips).
14. Fold the edges of the transparency over (like tabs on a paper doll) and secure it to the back of your layout or photo or wherever you want it. You can fold a transparency pretty easily (using a bone folder helps).
16. Acrylic paint - amazing but true - it works just like glue on a transparency (just paint the back and lay it in place - as it dries it will secure the transparency).
17. Use a small hole punch to punch a couple of holes through the layers of your project (including the transparency) and secure them all together with tied ribbon (or make more holes and "weave" the ribbon through them).
18. Crystal lacquer.
19. Photo turns (with some adhesive underneath them), Conchos, nail heads, index tabs and clear adhesives (there are a lot on the market).