I have found at Joann's that they have two turn-around things right when you walk in that has a bunch of scrapbook items and they are all only $1. They have some REALLY cute epoxy stickers that are different shapes, colors & patterns. I am going to try to attach a picture of them
Sorry if it's huge, I don't know how to make it smaller. (And excuse the wrinkly tablecloth!). Anyways, I thought the stickers were pretty cute. I have used them on top of a larger plain button to add a little color, too. You can also use this tutorial to add glitter to the middle of a fuzzy center. Sometimes the flower centers aren't too bad, and this is an easy way to add a little glitz to it. Flower centers - experiment - Posh N Pretty Forum
I have made them this way, but I HIGHLY recommend brushing the glue ONTO the flower center w/ a paintbrush so that the individual "bristles" or "hairs" of the flower center get coated. If you just dip it in glue or glob it on, then put the glitter on, it makes it look like a glitter-covered gumdrop, so it didn't look so hot (I threw it away). It does take awhile for like the Alene's tacky glue or whatever (also I don't recommend hot glue for this) to dry w/ the glitter on it. Also, you can use glitter glue from the craft store, that worked well, I just squeezed out a little on the tip, and "brushed" it on with the tip of the bottle. Does that make sense???
Also you can make your own covered buttons w/ various types of fabric & use those for centers. You can get some really good ideas just by going down the scrapbook embellishment aisle at Michael's or Hobby Lobby. There's just SOOOOO many options!! Have fun with it!!