TL;DR: Don't just be a male, be a man. Be a man, and you will be a god.

Let me get right into it:

Virtus

The Romans had two conceptions of what those with an X and Y chromosome are. One was homo, the other was vir. A homo was simply a male; you were born as such. A vir was a man; you became as such. The Roman philosophy of manliness, or virtus, is incidentally where we get the word "virtue" from, but this word has lost its gendered connotations and the potency of it has therefore been watered down. The Romans would laugh their asses off at the notion of a "virtuous" woman.

Virtus contains components which I think are not only extremely RP but also extremely relevant to modern men. I'm going to tie it in with the Roman concept of power and split it into Personal and Interpersonal categories. To keep things (relatively) short this will be more about the "what" than the "how." The "how" will vary with each person anyway. I thought I'd lay these out for you guys and let you take from them what you wish.

[Personal Conduct]

Dignitas

The word "dignity" derives from Dignitas. But whereas we only mean it as the avoidance of humiliation, the Romans had a deeper meaning. Dignitas is not just the protection of your honor and prestige but its cultivation and expansion as well. Great men have always had an "aura." or charismatic presence, and Dignitas pertains to what a man does to increase it (or create it if he totally lacks it). To put it in RP terms, if you practice Dignitas you are not merely 'holding' your frame against constant attacks from outside actors. You're also trying (and succeeding) to draw people into your frame and thereby brighten your aura. Dignitas has an aggressive and transcendent quality to it which "dignity" does not. It has to be won, not just safeguarded.

Gravitas

Gravitas is a weight and depth of character and people being able to sense this weight and depth. "All I do is hit the gym and hookup with chicks bro!" is not Gravitas. These things are good, but not by themselves. Gravitas doesn't only have connotations of a serious person. At least, not serious in the sense of a dude who walks around rarely smiling and never having fun. Gravitas is having more than one facet to you, like a cut diamond. The whole diamond doesn't gleam, only certain facets depending on the angle. It is having more, far more, to you than might immediately meet the eye. To put some RP in it, the RP concept of mystery is impossible without Gravitas. If you're a shallow man then any vagueness or withholding of information will only look like shadiness and hiding. Of course on the flip side a shallow man who reveals everything will quickly become a boring known quantity. Only a deep man who is seen to be deep can generate the interest necessary to have others wanting to get to know more about him.

Pietas

If this looks like the English word "piety," it's because it's where the English word comes from. But again (notice a pattern?) the English definition doesn't do the original much justice. Pietas is deference to the gods, to be sure. But it also entails a sublime respect for one's forefathers and elders. Pietas is respect-on-steroids for those who came before you and the proper order of things. It also carries connotations which we might call obligation or duty. It's not enough to appreciate that the world was here before you: you also have certain obligations to improve what sucks and honor what works. I'm sure this doesn't fit well with the mantra of amorality you see in much of TRP, or the hedonistic creed of Western societies in general. But with Pietas any "decline" means that men have fucked up, and that there is nothing "enjoyable" about this. There are certain things men must do to uphold civilization so that the work of the ancestors and the will of the Heavens (if you believe in that sort of thing) do not go to shit.

Bona Fides

This simply means "good faith." English retains this term verbatim (albeit mispronounced) and uses it to mean "the real thing." But the English definition is only the end result of the Roman definition. As a Machiavellian motherfucker this is probably the hardest one for me to get my head around, but it's still true. If you conduct your business in good faith you will come to be seen as the the real deal. Act shifty and fuck people over at every opportunity, and you are laying the groundwork for your eventual downfall. You can only outrun fate for so long, and in any event why would you want to spend your life running? Be just until you absolutely can't, be honest until you absolutely can't, and you'll build an empire on solid foundations.

[Interpersonal Conduct]

Allow me to invert Oscar Wilde's famous quote and say that everything is about power except power; power is about sex. Same end result but with (in my opinion) a more appropriate emphasis. All interpersonal relations are ultimately about who has the power. This applies to the men in your life as well as the women. But what is power?

Potestas

Potestas is power derived from force or the threat of force. Full stop. I can make you do what I want you to do if you refuse to do it. This is where TRP emphasis on lifting is so useful. You have to be able to physically enforce your will on others even if this is simply the will to defend yourself. You need an immediate answer to the question "what are you going to do about it?" beyond just whipping out your smartphone and dialing 9-1-1. I once heard that charisma is the combination of glamour and intimidation. I don't think that definition really fits "charisma" but that's not the point. Possessing intimidation is vital for men, and it is impossible if you have the same body you did when you were 12. I have mixed feelings about the fact that men can no longer recruit an army and go take what they want by war, but that's the world we live in. Your Potestas has to be individual, so lift. But you need something else as well, because Potestas without Auctoritas is false Imperium

Auctoritas

The caveat that everyone forgets about Machiavelli's famous quote is that it's better to be feared than loved provided you are not hated. Auctoritas is the key factor in achieving this. We get our word "authority" from this, and (for once) the two definitions mostly match up. Power via Auctoritas is power from prestige and authority rather than mere intimidation. Another way to put it is legitimacy. In the Roman Republic the ruling Senate actually had no Potestas, only Auctoritas. It gave advice which was "less than a command but more than a suggestion," and this Auctoritas allowed it to rule Rome for centuries. But of course you need both, because eventually the Senate ran into men who didn't give a fuck about its prestige and overthrew it with brute force (though it's interesting that these men were all Senators themselves). Auctoritas without Potestas is false Imperium.

Imperium

Imperium is power in its ultimate form. Victorious Roman generals were hailed by their troops as "Imperator" (basically "power-wielder"), and the Roman emperors incorporated it into their many titles so often that English gets the word "emperor" from it. Imperium both includes and transcends Potestas and Auctoritas. Without one or the other Imperium cannot truly exist, but it is also greater than the sum of its parts. This is difficult to explain in English but maybe one way is to say you have complete jurisdiction over all aspects of your life. This is should be the end goal for all men. Transcendent, sublime, supreme power. Maybe not over nations, but certainly over your personal life.

[Ye Shall Be As Gods]

The English word "religion" comes from the Latin religio, which in turn is from religare. Both Latin terms mean something like "binding." In the Roman case this was a binding of oneself to the gods in the hopes that they'd reciprocate with blessings. If you can integrate the above philosophy into your life, or something similar, you will inevitably have others binding themselves to you. Masculine men are an increasingly rare commodity and human beings innately desire what is rare Fuck building a personal "brand." You will build a personal religion. Both the men and women in your life will follow you anywhere. This is especially true in today's feminized world where true manliness is unknown to most men and unseen by most women. I know every generation thinks the past was more masculine but we really take the cake. Our societies openly favor the feminine and contend that gender itself is both a personal choice and a social construct. But by lowering the bar so low our societies have made it that much easier to look celestial if you rise above that bar. To be a vir among homos (and women) is to be a god among men. There is no difference.