What could I do for my bf while he jerks off to me on call?

I’m currently long distance with my bf and he jerks off to me in call usually, I’ll typically sit there naked and watch him sometimes masturbait with him typically just rubbing or using a vib but what things could I do other than that? I wanna do more for him but Idk what! Especially like if I’m on my period what could I do I’m not into masturbating then personally too messy for me lol. But I just wanna be less boring than sitting there and do something more for him :)!