There ya go. Yeah, I didn't mention it but that is an option too. Usually the quality is better if you can afford to buy them already finished.
When you do it yourself, esp with the stickers, they come in sheets of 50 or 100 I believe which means you have a lot so you can do more than one project with them which is what I do. Magnets, I just make the cover of the book. Most of my friends proudly display theirs on the fridge so when their other friends come by they can tell them they know an author which is cool. I like that!
It really does depend on what you can afford, either way is great.