>>292509246
It's older than time. It's important to be subtle at first though. You can't go right in with the "shaking salt into your mouth while looking up" right away. You say hello, you headpat or get headpatted. when someone touches you, you react as if you've been wanting affection your whole life and this person's touch is exactly what you want. Just a bit. 
If they back off, or stop, or seem uncomfortable, ramp it way down. If they seem comfortable or even receptive, ramp it up. 
It's a slow process to warm someone up, and there's variation between people. Some people will whip out a dick then and there (and they're fucking annoying, stop doing this you fucking gamer), others will back off while still being partially receptive. It's a spectrum. 
Try not to be too much of a slut though; don't be affectionate with too many people at once. There's a human instinct to feel bad when someone you like is being petted very affectionately by another. It's not pleasant, and it drives some people absolutely mental with jealousy and rage. 
It's a balance.