How to improve oral sex on my man?

Okay, so I feel like my bf is getting bored during sex. I always want to improve, especially with oral sex, but I just don’t know what to do & sometimes I feel so shy to try new things (I have no idea why).

We had a talk the other day, & he told me to not be scared to try new things, he said just going up & down becomes boring after while. Is there anything else I can do to turn him on? Can you guys give me some ideas?