12 is WAY too late an age to start, are you kidding me??? Your only chance now is for him to see it through your unconscious actions about how much better being strong tough etc. is than to be a weak simpering wuss, and you’ll have to wait until he really hits puberty for it to happen before it’ll do anything. You should have engrained in his mind from before he was even to walk about strength and toughness (not lectured him on it, just side comments here and there about certain things). You have to show. Now that he is 12, you’ll have to show it more than ever, but gradually, not right away.
At this point, if he and you both want something and butt heads on it, you’ll have to let him have what he wants on the smaller stuff. For big stuff though, don’t let him push you around, you still need to show that you’re still a man too. Just be a masculine presence in general. When you think of the words ‘strong’, ‘tough’, ‘masculine’, and ‘dominant’, what do you think of? Whatever you envision, try to tell yourself that so that you become it and exhibit it. But still take a keen interest in what he says and does when he is talking about something that he’s passionate about, and try to smile like it’s interesting for you. The reason for this is because it validates him to have the alpha male, and someone who is presumably more dominant than others he comes across, take an interest in what he has to say and he will think of himself as important too. Don’t give him unnneeded or undeserved compliments though unless one day you just really notice a big (positive) change and just randomly say something like “wow you just look really strong right now” or something like that. It doesn’t need to sound as gay as that did right there lol but you know what I mean; they should be rarely given, and probably won’t be given to him at all until he gets to 14 or 15 or so. But yeah, take a keen interest in him while exuding a strong presence because it will make him feel a lot better. You might be thinking how he shouldn’t have to need the validation, and that’s true for others. But you as parents need to understand that they as your kids NEED this validation TEMPORARILY until they get set on their own. You hold the foundation for them to stand on, and you need to lift it higher and higher until they can grab onto the next ledge and heave themselves up by themselves so that they can stand on their own; typically, them heaving themselves up up over the ledge and trying to stand on their own (metaphorically speaking of course) is when they are in the middle of high school and get to college, and are at the point where they are figuring out what they like, ‘who they are’, etc. With kids, you need to understand that before they can stand on their own, they need support. Weakness from craving support and validation from others is where the line is drawn, but seeking it from parents is where their core being is shaped and you need to help culminate that into something strong, tough, masculine, yet still understanding of the laws and rules around them (lest they end up in prison, but usually that only happens when kids need to prematurely be strong in order to survive, and oftentimes they end up just killing themselves, become extreme drug addicts, or start shooting everyone up anyway).
There’s a lot that I could say right now, but it’s too much to type anyway. You might also be thinking “well this seems like alright advice but why should Inlisten to an 18 year old?” And that’s because I myself still remember every time my parents ****ed up when raising me. I still have memories from before I was able to walk, from before I was able to crawl as crazy as that seems (**** happened when I was an infant lol). I still argue with my parents like you’d expect, in fact I’m currently holding a battle of attrition with my father right now haha, but it’s only when they’re not listening to what I have to say or are just being pigheaded and stubborn for sake of ego and pride. Otherwise we’d never fight. That’s another thing, always listen to them and try to understand their logic and reasoning for things no matter what. If there is a fault in their reasoning or logic, tell them after they finish speaking so that they they can correct it. It’ll be a step-by-step process and sometimes you two might disagree on how things work, but still listen and just try to agree to disagree if it gets to that point. The biggest thing that I can say that will affect them when growing up are probably nuances. The nuance to everything you do from your body language to tone of voice is huge, and not just that but also how you are when you’re around him and when he is watching you while you don’t know he is. That stuff is important.