Be the one holding the whip and nobody will wonder.

I haven’t found sexual dominance in guys to relate to their size or body type. Would say for pictures direct eye contact, and strong posture show confidence. You like your build, yes?

Despite what the internet would lead you to believe, body type is not directly correlated to being dominant or submissive. Neither does gender, sexual orientation, clothing or anything else on the surface. The type of person you are sexually, your preferences, your kinks, are only going to come out when you sit down and talk to your partner - or viewers - about it. Otherwise, its just folks making assumptions - and generally forcing standard hetero-normative gender roles into non-standard relationships or people. A big, bulky, tough guy can easily be submissive in bed, just as a soft-spoken, short man can be a cold dom. And the idea of a bottom dom would make some dude’s brains explode. At the end, its about personality, not looks.

So the answer is, unfortunately, this isn’t something that can be “fixed” because its not a personal problem. Its just people having an uneducated perspective of how sexual relations work.

As a formerly lean male, I’d say don’t be afraid of becoming a bit less lean. Consistant weight lifting will change how you see yourself. You don’t have to be a body builder. Even a small amount of muscle showing is worth it.

A lot presenting as non submissive is posture.

Stay upright, shoulders back, and half the job is done.

Keep your arms controlled. Doesn’t matter if they’re in your pockets, moving at your side, it they’re crossed, they just need to be controlled. No fidgeting, no clutching them.

The head being upright, while making eye contact helps a lot in presenting as either dominant or at least not submissive.

Think about it as owning your space as well. You don’t just own your body, you own the space as far as your arms can reach. I’m not talking about refusing to let anyone into that space, is about how you think, because that changes how you move and present yourself.

Watch people in a crowd sometime. When someone needs to get through, do they duck, and bend and squeeze through, or do they move with intent and ask for space to get through? You can be assertive and even outright dominant without being a dick. A tap on the shoulder, an “excuse me”, those are not submissive, they’re polite

Clothing wise, unless you’re hitting a kink club, I’m not sure it matters. I’ve known many a dominant “twink” in my days, and they don’t really dress different from other body types on average unless it’s in a place where people are all dressed for roles.

A side note: back when I was bouncing and otherwise doing security for clubs, twink always meant both lean and feminine, as well as either submissive or non dominant. You did run into some power bottoms that called themselves twinks though. It’s always interesting how terminology shifts over time and by location.

I’m not the best one to ask about how a guy can look sexy. Cishet, so I just don’t see the male form as sexy at all, I’m limited to whether or not an outfit is flattering, I can’t rely on attraction to guide it.

That being said, lean guys are most aesthetically pleasing when they favor clothing that accentuates their body lines. Pants and shirts that are close to the skin, with maybe something looser over top. Back in my younger days, one of the more popular styles was tight jeans, a form fitting single color tanktop or tee, with a silk shirt in a complementary color over that. The over shirt gives motion and a visual pop, while the rest makes the body the focus. That’s the basic idea I’m talking about.

When you’re lean, as opposed to athletic or outright muscular, it’s all about how the lines of the body flow vertically. Play into it, particularly with the abdomen and chest. If you’ve got more muscle, you can emphasize those areas, but it comes down to the overall view if you’re on the edges.

If you’ve put time into your pecs and arms (some lean guys do), don’t be afraid to show them off. Shorter sleeves, a tighter fit across the chest so that the pecs pop more.

It’s kinda hard to be specific though, I’ve never been a clothing/fashion kind of thinker, I’m just going off of what I’ve observed being successful in terms of guys not leaving a club alone when they have that body type, and how the general style looks when photographed.

But, for real, most of it is in how someone moves, and that’s largely based on how they think of themselves. There’s exceptions for sure, but when you’re in a setting like a club or bar where you want to attract partners that are going to match your dominance/submission preferences, the more you think with confidence, the more you act with confidence, and that presents as being more dominant in your preferences, even though confidence isn’t inherently dominant, nor is inconfidence inherently submissive. We’re just talking looks and impressions here, not actual personalities and psychology.

And when it comes to that, nothing is as important as posture, eye contact, and owning your space. People respond to that.