keep at it, look at what the other artists do and use there techniques to further improve your art, that said you have talent. keep on sharpening your skill set ... with Brilliant.org (was a joke, you will know from the YouTube sponsorships that is on that keeps getting mentioned to the point that its predictable), seriously keep on doing what you are doing

you can use more color and gradient in a subtle ways (like shadows, similar to what you did on the hair tentacle but less saturated in some cases) if you want, I would reconsider using that bristly looking brush spray in grey. nice idea on the white outline that was cleaver like that was a pro move, from observation no doubt.