I have made tons of peel and stick decals using Paint Shot Pro graphics program and ink jet printers. I like the waterproof vinyl media from papillio the best, easy to handle, takes detail well. One warning, if you use inkjet printers do not use refilled ink cartridges. You have no way on knowing the quality of the ink and you may encounter very fast deterioration of the color quality in the sun.
1. Design it.
2. print it- let it dry a few hours.
3. Spray it with fixative, papillio has one that is excellent, but if you buy from the paint store get a fast drying that says it offers UV protection. Let it dry a few hours.
4. Measure the blank circumference and cut the decal to fit that dimension. A little overlap is not a problem since the media is so thin the overlap gets hidden by the wrapping epoxy.
5. If the background of the decal is dark, darken the edge of the decal with a sharpie to prevent a thin white line from showing.
6. Install it. Position it carefully and install on the blank, the center first, then work it down from the center to the edges.
7. Take a hard smooth tool, like the winding buffing tool, and with a protective sheet over the decal (the backing works well) give it a good, firm rub down to force the adhesive into intimate contact with the blank.
8. Put a little color preservative along the edges to help seal the edge from the epoxy and prevent lifting. You need not put it over the rest of the decal as the fixative protects that.
9. I design my wraps and decals so that I wrap over the ends of the decals.
You may have to play with your printer settings to get the color/quality you want. I don't recommend trying to match the blank color-it's almost impossible. Better to choose a contrasting color that doesn't rquire exact matches. Follow the instructions of the media supplier. Papillio offers a clear decal media, and I have used it with success. It doesn't have the shelf life of the white, though, so I don't trust it unless I use it soon after purchase. It tends to separate from the backing in storage.
If you plan on using the same decal design multiple times, like a standard logo, I would recommend Decal Connection. They are great to work with, can do any color, even metallics, and you don't have to worry about fading.