Step 5: Application (The fun part)
Find a good, flat surface to put your sticker on. Porous surfaces tend to work best, but sometimes it really depends on the amount of adhesive on the sticker. Use your spray bottle to give the adhesive a few good sprays so that it's all covered, it's good to spray from about a foot away so it doesn't get too concentrated. Too much water will make the adhesive too watery and not dry as well and not enough won't activate it, you need to play around with it. If you don't have a spray bottle a damp rag will do. Just brush it over the surface and slap it on.
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.