I know some bow makers use wire to put the layers together, some sew, I mostly use hot glue. As for ideas, I love looking on ebay to see what new things people come up with & also on etsy.com. It's inspiring to me to see other people's creations
As for putting colors together, I mainly make bows to match my kids' clothing. So I put colors together that are common in their clothing -- pink/brown, pink/white, hot pink/apple green, etc.