I'm the same age as OP and in my experiences it's 90% confidence 10% subtlety, my last 2 girlfriends I met while at work, they come in asking for help. I give them help and a little bit of flirting, with a nice smile and confident speech, girls will start to fall at your feet. All because they're sick of the guys who are way into them but shy and creepy about it.
A huge amount of that confidence comes once you've already had a relationship, but the foundation comes from just being comfortable with yourself, don't be so afraid of rejection, it happens to everyone and it just shows you it would never have worked with that person to begin with.
Get yourself out there, go to some bars, get a job, find an outdoor hobby. Anything to get you talking to people building your confidence.
That is if you want a decent relationship, if you just want meaningless sex then bar, drink, fat girl, done.