all you need is:
3. Glue gun :)
Step 1: Arrange your cabochons according to your designated design.
Step 2: Stick your cabochons on your Sunglasses (make sure to stick them properly and be careful while sticking your cabochons on your sunglasses)
Tanan! You're shades are done! :)
Or you can also decorate your shades like this (by putting all the cabochons on the upper layer)