Hello Melinda :)
The first step is learning to flow with the canter of your horse., by focusing on his rhythm.
To create more bounce, you can apply half-halt aids to encourage your horse to rock his body even higher and thus create more suspension.
To produce a good half-halt, sit in the middle of the saddle with your ear, shoulder, hip and heel in a straight line, while engaging your core and bracing your back. (For readers familiar with karate, this is much like the feeling of a karate stance. I help my students practice by standing next to them when they’re mounted and trying to push them off the horse. The strong, centered feeling they use to resist my pressure is the same feeling you want to have during your half-halts.) Then—always after your seat aid—add a little rein pressure without pulling your hands backward.
Hope it help :)
Well other than ones already mentioned, collecting the canter, small circles and slowing the canter tempo. Also doing lots of canter-walk transitions.
As Rebecca said, the ground pols or cavaletti, relax your horse's mouth and repeat it! After he'll be careful and be more bouncing than he used to, but be patiente and you'll get what you want :)
You should try ground pol and make sure he doesn't rush, and he'll articulate himself and bouncing much more!