Step 5: Application (The fun part)
Apply the sticker to the surface and hold it there for a second. Be sure to flatten out any wrinkles or bubbles. If you didn't weatherproof them with tape or plastic you can give the face of the sticker a few sprays to activate the adhesive absorbed in the paper.
Remember: These stickers can be tough to remove, be mindful of where you put them.
That's pretty much it. The few stickers I've made have been in high demand from friends and peers. I've also passed them around at concerts and given them to potential clients. It really helps to print out a bunch (if you have a good printer with waterproof ink) and make a bunch at once, cut out a few and keep 'em in a baggie. However, if your design's shape is complex (like the Cthulhu sticker) then be prepared for a world of hurt when you cut out sheet after sheet.