Sorry for the bad pics, I don't have a camera, so I can only serve pctures made with my phone.:[
AAAAnyway I hope you still like it!
Its really easy!
Gather your supplies!(I was too lazy to photograph them all...)
First decide, what part of the picture would you like to be on the pin.
If you have decided, put the glass stone on the pic flat side down, softly outline it, then cut it out.
Now dip your paintbrush softly in the water drop a few drps of mod podge/découpage glue on it, then brush it on the flat back of the stone, insert your litle pic on it.After that drop a few drops of the mod podge/découpage glue on it, brush it.Leave it to dry.
After it has dried superglue the pin to the back of the glass stone, wait 'till it's dry and here you go! It's done!