I've made them by getting a clear bulb and rolling up the picture to fit through the top, then carefully unrolling it with a pencil. Then add either confetti, tinsel, or snowflakes and put the top back on and tie with pretty ribbons. I've done it with different sized, shaped clear balls, flat round ornaments, and different filler, etc.
Last year at michaels I bought some kind of magic bubble kits. it's sort of like decupaging fromt he inside. You put the picture in and use the magic glue, then put glitter in and it glues to the sides everywhere around the picture. I'm goign to try it.
I also like to buy the pretty ornaments from Michaels that have a whole for a picture. I got a bunch after christmas for $1 last year. I usually buy them when they go on sale for 40% or 50% off. They are reguarly $2.99.