Robots are really nice and i love your work its so cute, if you want to be more varied try leaning parts of other things it could be animal legs or anime eyes ( my favourite ) or even camel toes .... as in the toes of a camel.
but really try just drawing random things and see how it goes. might draw an animal legged anime eyed camel robot with wings...
anyways try youtube for inspiration ^.^ and keep in drawing you have more tallet than me :3