I'm sure you've seen these all around the blog land like I have and I was in the dollar store the other day and saw their ornaments and I couldn't resist making my own. There are some great tutorials out there such as: Thrifty Decor Chick and Eddie Ross and Just a Girl. They all give some great tips on how to put the wreath together but the next time I'll make a few modifications.
First, I would use craft wire instead of a hanger. The hanger was a little thick for my cheap-o ornaments which made it hard sliding them on and also it was difficult for me to finish it off nicely, HENCE, the giant bow.
Second, I might reconsider the dollar store ornaments. It was nice that they didn't shatter on me (because they are plastic) but even after super glue the top to the ball part I still had issues with the "hook" breaking. If I put a little too much pressure on the bulb it would snap and I ended up using super glue to put it back on the wreath.