For guys, on spouses:

Know that the only couples who last for 20-50 years together are ergregiously compromising (generalism yes, but 99% accurate). So prepare for that end on day 1, and move on as soon as you're not good for each other (or the kids).

First wife must be able to pay her own way. Makes a massive difference in life if you're able to save when you're young. Even better if one of you can study or start a biz, when the other is earning. People who get that right are always way richer than those that don't. (And don't fuck her over in the divorce...no one needs that karma).

But once you have money, find a wife who's bisexual and hot (or maybe that's you). Agree on the first date that threesomes are a regular thing. Once proven, marry her, and neither of you will ever stray, and you'll have the most amazing life; social, travel, festivals...all with your third, who will rotate, but each will gain as much as you do. Don't compromise. Don't be a pussy. Even put it in your dating profile "looking for hot bisexual lady for life of travels and threesome fun". You don't want the ones who don't get it anyway.

Sounds brutally harsh, but I've socialised this thinking with around 20 highly successful +50yo males, and there's strong agreement...from those that got it right, and those with regrets, who now have to use hookers or mistresses instead. Wish I'd learned this 10 years earlier. And my bi wife agrees too.

Oh, and as an aside, get into gym on the reg. Makes all this so much easier and fun. That's also where you'll likely find that hot bi wife btw.