This has far more to do with attitude than anything else. The fact that you're asking this question means that you are not a sarcastic d-bag or a sociopath. If you were a sarcastic d-bag, you'd just continue to internet troll, act like a jerk, and treat people like crap to improve your game. If you were a sociopath you'd continue to disregard people. Either way, at least subconsciously, the people around you would respond in the way you are looking for...because they would confuse your indifference and crappy behavior with being capable...and they'd fear it.
Since you are neither of these, it will require a bit more work to get where you want to be and some of it will be unnatural for you.
Here are the three things that frame the rest of the discussion:
1. People want an Alpha to take charge - my daughter calls them metas (as in meta humans). In simple terms, you can think about it this way: why does our culture pursue sport teams by spending their time and money to learn about and associate with these teams? It is significance by association. Either association with the vaunted position of coach or owner to validate *their* intellectual position. Or association with a player to connect with their physical prowess. This is basic, but I hope it makes the point.
2. Your task is to achieve the dramatic, not the actual. You're wanting to be perceived as Valdemort, not cast spells like Valdemort (I hope). Consider it this way: Daniel Craig has far more in common with his character in Dragon Tattoo than with 007. There are no real 007s who can drink a gallon of scotch (or 12 martinis, shaken not stirred) then shoot multiple assailants with a .32, at a distance of over 25m, with a heavy crosswind, from a moving vehicle. Then fall multiple stories and kill a man with bare hands. And, finish with an hour of passionate (successful) love-making. Your objective is to help people believe this is possible, not demonstrate that it is possible.
3. You can dress to be pretty or you can dress to be powerful. Sometimes there is cross over, but not always. For instance, Southern Trad (aka. "I spent a lot of money to look like I shop indiscriminately at Goodwill") is attractive, fashionable, and it looks cool. But...and this is a big butt...it conveys acquiesce, not authority. That is, it appears as though you are "giving in" to the responsibility to maintain your appearance while demonstrating contempt...and NOT like you're grabbing the responsibility and owning it. It's ok to dress pretty, just understand that it is counter to your desire to convey authority.
About a year ago, I walked into a Nordstrom, in a suit, with my wife and our two children, just to shop: no weirdness, no strutting. Keep in mind, my children and wife were standing right there the whole time. One of the ladies hustled over to me. She said, and meant, "Oooh...I thought you were House!" She was breathless. "I love House, oh my." More breathlessness. "You look so nice." And it went on for a few minutes. I thanked her and smiled all while giving her intense eye contact. And, left her breathless... FWIW, this type of stuff is daily, almost everywhere I go and almost all situations.
I look NOTHING like House. I'm 5'9", bald and I usually have a heavy beard. My wife and I still laugh about this exchange. She even makes fun of me (once in a while) by calling me House. Regardless, what that lady wanted to see, needed to see, was someone who (in her mind) seemed authoritative and powerful. She didn't know me and she never really even saw *me*...I mean, the real me. I let her see what she needed to see. And it made her happy.
Also, I'm not Valdemort, or 007, or whoever. I'm just me. I even explain to people exactly what I am doing...what I'm explaining to you here...and it has zero impact on their perception.
These are guide lines to make this easier. You can break or ignore any of them, but you will have to "up your game" in other areas to compensate.
1. Talk less. Listen more. Maintain eye contact: chin slightly down, eyes up.
2. Don't empathize. Acknowledge the persons attempt to confide/communicate, but receive it as a parent who must teach the person to overcome. That doesn't mean you discuss their issue, just receive it as though you are weighing it. Remember, you're not an a$$hole, you're a person of authority who respects their need to communicate.
3. Do not participate in ANY office grousing or woe-is-me discussions...ever. Listen if you must, but NEVER participate or pass judgement. Again, you are the authority figure who is stalwart in the storm and you respect that they are venting.
4. Always wear a dark, solid color suit and NEVER take off your jacket when you are with other people (as the dress shirt is actually no different than underwear). Only in private do you not wear a suit. You'll get used to it...
5. Solid, muted, understated ties: black, gray, olive, navy. MAYBE eggplant/plum on Friday.
6. White shirt only. Blue shirt conveys that you submit to someone else. Colors project vanity.
7. White linen or cotton pocket square...always.
8. "Casual Friday" is not something you participate in. At most, you still wear a dark blazer with your jeans...white shirt rule still applies.
You're conveying an image of someone who is not frivolous or fancy. You're the authority. You're concerned to display that you will always do more than your peers, you'll always do more than you are asked, but you're not arrogant about it...it's just how you are.
You have to come to terms with what you are asking: You're changing your life...not strapping on a persona. You're deciding to be the meta that you wish to be (i.e. you're a human choosing to do the best you can do...always).
All of this is a bit easier for me because I live in Atlanta and no one here knows how to dress, or to act, while in public. Lots of people wear ties with khakis...that's not dressing. Some wear mismatched jackets and trousers and they take off the jacket when they get to their destination...this defeats the objective in the first place. So...any effort I put forth is magnified by the absence of effort on everyone else's part.
Of note is: ability. Ability is important, but probably not in the way you think. Ability is not what will convey the authority you're looking for. Ability is personal and usually just changes the shape of your day: If you have ability, your day is easier and you can concentrate on other things. If you don't have ability, getting through the day is tougher and takes more time. Regardless, you can lead and motivate without ability.
Here's some bonus material. An "attack vector," if you need a place to start. But I need to provide a caveat: I am hopelessly in love with, and devoted to, the most amazing women in the world. I seek no other and I will not receive another. Here we go: I cultivate relationships with the women around me (remember, suits are to women as lingerie is to us). Why do I do this? Three reasons:
1. Conversations are always warm and friendly.
2. There is always an opportunity to advertise a successful interaction with the people around me...without looking like I'm fishing for it.
3. Every man around me knows that I am dominating the room...and I never have to take a shot at "the enemy." I go straight for the treasure while they're fighting it out with one another for superiority (If you like to fight and you're capable of winning, that still has nothing to do with the poise you are looking for. People fear a bully, they do not respect one).
If you're gay, this may look a bit different, but you can make it work...you'll have to do the tailoring. I worked with a big gay Texan...but I didn't know he was gay for over a year. The thing is, I don't think I've met a woman who wouldn't have swooned at this guy. And, he really only ever looked like an average guy, but you never perceived him that way. He was 6' tall...maybe 6'3" with his boots. But...he never looked any less than 7'6". He always wore a suit. He always listened. He always maintained devastating eye contact. And when he took action he did more than was asked or expected. He never let his outside concerns interfere with his objectives and responsibilities. He was meta. Everyone knew when he entered a room. And..he made it feel like the right thing to do was always more than asked.
There ya go. Treat these ideas like Lego and start arranging them in a way that makes sense in your life.