While I, personally, would love to see more of your kinky side, please don't feel pressured to show it. Only do it if you really want to explore that part of yourself. Do not do it just because you think it might boost your popularity, because that is an unhappy road.

I don't think art trends are the way to go unless it actually sounds like fun to you. But you could try drawing some fanart. I like your OC's, though it couldn't hurt to test other waters, I suppose. Maybe experimenting with new characters or styles could be fun for you?

As for asking for areas of improvement, that is difficult. I could probably think of a few things, but the problem is, it can be hard to tell what actually needs fixing, and what's simply a stylistic choice that I wouldn't have made myself, but is still valid. I'm happy to have that discussion if you like, but I do want to put that disclaimer first haha.

I think a good thing to do is to ask yourself "where do I think I can improve?" And really think about it while looking back through old work. You'll probably find something. Then ask others for specifics on how you might be able to do that. Saying something like "Hey, I want to improve my character anatomy, can anyone recommend some good resources or practices?" will almost certainly yield better results in my experience.

I hope that helps some? I'm available via PM if you need someone to talk to...

I concur with everything Harry said. I won't repeat too much.

I think the mindset of wanting to improve is always a good one. It can be hard to be a critic to a close friend, and it can be hard to tell the difference between areas for improvement and stylistic choice. But I would definitely be willing to have that conversation with you if you wanted it!

I think you should ultimately do what you want. At the end of the day, doing art should be for your own pleasure. If you want to do more kinky stuff, then go ahead and do it! If not, don't.