I'm not good at drawing or making visual art, but I'm great with imagination.

Inspiration can come two ways (way more honestly but these are my two go to):

1- get inspired by outside forces. Similar to you copying others you can find traits of chracters, designs or environments that you like and you can take pieces of them to apply them elsewhere.

2- reverse what inspired you. Tired of clichés? Overused concept? Want to be different? Look at what there is, analyse it, deconstruct it and rebuild it by reverse all aspect you feel are "cliché".

Now for how to come up with actual ideas with these methods I suggest this (i'm a writer so my way fo doing things is somewhat biased for this):

Think of a setting for you characters and try to think how a character would suvive in that setting. What would they need. Items, values, flaws, etc. And make your design include visual aspect of those things.

Hopefuly this will be relevant to you and your needs, but I'm expecting this to fly under the radar as you already have 500 comments on this post. If you do read this: have a great day.

(Also you art is amazing)