The past three years we have made what we call Stained "Glass" Ornaments.  They are not glass at all.

First we design the ornaments using a print or graphic program.  We start with a circle, and then put our design inside.  The simpler the design the better.  You can use a different shape than circle, but those seem to be easiest for us.  I prefer to use Celtic knotwork or imagery inside of mine.  Here is a generic one we made last year.

Then we print it on inkjet transparencies in black using mirror-image setting.  Be sure to set the paper setting to transparency, otherwise it won't be very visible.  It would work much better to print on a laser printer using laser printer transparencies, since you wouldn't have the coating to deal with.  The inkjet transparencies are not cheap, but a hundred of them will last for a long time if you are careful with them.

Next we paint them using glass stain or sun-catcher paint you would purchase at a craft store.  We use both the type that has glitter and the regular type.  They coordinate well on the ornament.  Be sure to paint on the side that isn't printed on, otherwise the ink will get messed up.  This particular ornament is very intricate, and not for the faint of heart.

Here is an attempt at a picture of one of the ornaments.  The flash caused part of it to whiteout.