I'm not artistic in the sense of drawing, but I've had several idea for skins that are silly, neat, and maybe somewhat decent. I figured I may as well finally make a post about. Hope everyone likes these ideas.
The most recent idea: Pool Party Jarvan Iv. His Extending Lance could be replaced with either a pool noodle or a pool umbrella. As for the rest, his armor would include water wings, a floating vest (is that what you call it?) and some flippers on his feet. His ult would have him yelling out something like "cannonball" and the enclosure becoming the ring of an inflatable pool.
Second and third are themed: Clean Up Crew Katarina and Janitor Jax. I think the names of the skins are self-explanitory to the concept. Jax would be using a mop (insert pun here) and Katarina could be using dusters. Obviously they'd be wearing janitor (or custodian whatever you wanna call it) uniforms. Recall animations would include either cleaning up a mess (like they do in teamfights with the stragglers) or some sort of janitor cart.
Fourth, and my favorite, Farmer Nasus. Because Q. Straw hat, a piece of straw in his mouth, overalls, and a farmer tone in his voice, Nasus would be using a rake (cuz he's raking them stacks in). This skin would also have unique voice lines after hitting certain Stack amounts pointing out how "it's been a good harvest" in regards to his stacks. This theme could potentially be considered for Veigar and Sion (farming AP and Health respectively).