I think Costuming is an art because you put the Costume together, with your own ideas, like when you paint, you put in your ideas into the painting and make it your own. I think it is the same way with Costuming.
To help others around me and make the world a better place, wbu?
I would (for the first) work on realism in you art. know your features and be able to know how to reproduce them. It would be best to work on realistic portraits of other people, perhaps stock photos off the internet. For fantasy landscapes, I think that things that are trippy are good for fantasy landscapes. weird color schemes and similar things of that nature. hope i could help!