It's really about what you and your bf are into and comfortable with.
If you're adventurous you might want to try outside sex- either in the back yard (if you have a fence this works better) or maybe a place were you can fool around in a pool or hot tub? Even just some sex on a vacation is a nice change.
You could try another person if they are into that, or maybe just have someone watch you two have sex. Role playing can be a fun way to spice things up also.
Have you ever just given him a lap dance, did a little strip tease for him? Maybe you could make him his favorite dinner and give him a blowjob, guys aren't usually that hard to please. lol
Those are just some ideas, I suggest you ask your man what he really likes, if he's not shy then you might just get an earful