I Started to make a few designs by my own inspiration, with some stones like agatha, tiger eyes, and others!
I know It's not easy explain the process for here, but basically, its just draw the design in a paper, of print some one if you don't have to much ideas or you are not good making draw, that is my case, but however I always use something special!
Then, just with practices you can started to make your design like me!
You can use a saw and set the stone in the metal or you can also use wire fot set the stone.
The wire technique it's more easy sometimes, if you don't try a complicated design!