These bows are pretty easy, all you need is an alligator clip (you can get these at any store or buy in bulk at Sally's beauty supply) some ribbon (the width of your clip) and a hot glue gun.
You need to start by finishing the end of the ribbon (heat seal w/ a candle) then open up your clip and put glue on the inside top part of the clip. attach the back of the ribbon to the glue (below I didn't want the polka dots to show) then place glue along the top of the clip over the top part (don't put glue on the hing itself) and underneath along the bottom. You can put ribbon all the way along the bottom but halfway seems to work the best and allow you to grip more hair to stay in place longer and easier.
Once you have the ribbon attached to the clip you can attach flowers, pinwheel bows, buttons, or the make small bows like the ones shown above.
To make the bows shown above take a piece of ribbon and for a loop with the ends overlapping. Glue both ends together and then to the back part of the loop. Now you have two small loops with glue in the middle. Take a second smaller piece of ribbon wrap it around the center of the piece you just finished to hide the glue and glue the back to make the center of the bow. Now attach to the clip. Another option is to first glue the loop to the clip and then place the smaller ribbon center cover over the bow AND the clip (if you do this you will glue the center bow cover to the inside top part of the clip)