Since it was a serious question, I will give a serious answer...
I only did one-nighters up until the age of 24, which is when I got married to my first wife. Big mistake to get married so early!
Before marriage, a man has to be able to answer if the woman asks (and she should): "what will be the purpose of life for our family if I marry you?"
No way in hell he could give a proper answer before the age of 30. Therefore, no marriage before age 30, unless you want to be dominated by the woman and/or take on a HUGE risk -- that by the time you know what you want out of life, the woman beside you will be the one you want.
As for looks, easy, anything that makes Willie stand at attention...no magic formulas...look at her, and if Willie stands up, well, you have a winner.
The girls in the winky's pictures obviously know their market value and they intend to cash in on it. It's written on their faces and in their gestures. I could never get turned on by such girls...built in defense mechanism maybe I dunno. I go for the shy type, but still insist on certain things like not being overweight and having a cute face and not looking strong or boyish.
IMO if you are under 30 you should not be looking for someone to have your baby yet. Up to 25 the best is just to have as big a variety of experiences as possible. After 25 you should start thinking about the meaning of life without influence from a girlfriend. If you have a girlfriend, make sure she doesn't live with you and absorb all your energy. You need to develop without that influence. She will be pushing her own needs and not yours and you need space to figure everything out. Then around age 30 a notion of what you are about should have crystallized and then it's time to find a wife.
As you develop, your pecker will develop with you and will be attracted to girls who can fit your philosophy. Work on the philosophy and leave the rest to Willie.