Truthfully you will just end up raising children who feel they do not belong anywhere.
Well mine are CF's who feel they belong everywhere and can cross social classes backwards and forwards comfortably.
(TBF I don't feel I belong anywhere, but never did anyway so nothing lost there)
Cultural capital / education, all the way, and give each a name at birth that sits just as easily on a street sweeper, a clerk, a manager, or a judge.
For us it meant turning to Home Education to break a generational lack of education, 'XYZ' isn't for people like us, the crime of having ideas above our station, and the belief that just working really hard got you somewhere better.
I did a lot of time watching nice MC and UC families and figuring out what the real differences between them and me were, and adopting my version of what I thought was valuable, and not what I didn't.
Buy a table, eat at it, teach basic table manners, and talk about everything from whats gone on in their day to what's going on in the world.
Read and teach them to value it. Encourage them to share what they've read.
Keep a dictionary and a Theasaurus on that table, and let them use them to win in scrabble- make up your own rules and ignore cheating that has them read 'extra' words.
Play scrabble, chess, backgammon and Monopoly, they teach a lot of skills while having fun. If you can manage Go, do it. Nowadays, make Wordle, Octurdle, and Countdown, family stuff.
Stick radio 4 on in the background, turn it up if anything interesting comes on.
Turn them out dressed well enough to not feel lesser if you can and teach them to polish their shoes. (sounds mad, but got spotted a lot)
Teach them to value what they have.
Teach them to love and respect nature.
Teach them to speak to everyone, old young, regardless off position, and basic politeness. Good morning goes a surprising way.
Learn some basic Latin with them. It's really easy (Beginners level) the route of so much and Harry Potter helped it be cool.
Encourage learning another modern language just for the sake of it, get passports and get on the ferry day deals and use it.
Listen to how you speak and if you can't change your pronunciation, teach them they don't say it that way! (ie I say couwk and bouwk and bin but corrected the kids to say cook, book and been, automatically.)
Hand on every WC skill you have. Them having different skill sets (especially with education on top) opens up doors too.
Model hard work, but also smart work. Get them earning young and teach them to stay away from benefits unless they truly have no choice. (take the Kings shilling, you dance to his tune.) Go without or work longer to get what you want.
If it's free and involves culture, or making, do it.
Acting groups help with self confidence, teamwork, interviews and delivery of speeches/presentations or standing up in court, (LEA) and they're fun.
Don't sneer at Sebastian and Norbert, they have their own crosses to bear.
IMO being able to hold your own in any company and refusing to feel lesser (even if you're faking the hell out of it) imprints on them to actually be that.