Spicing things up

Me and my bf been together for 8 years and he saids he would like me to do more or surprise him with something. Which i feel is fair since i rarely get on top when i do it’s not for long bc my legs give up so I try to make up with giving oral and I normally let him leads bc im still shy more self conscious about my body so i like for him to start but besides that what other way can i wow him or tips on riding on top