The truth is that most men are really handsome if they just take care of themselves. Your clothes don't have to be brand name, but just make sure they're not sloppy! Being a bit overweight is fine, but flabby and obese is unattractive, mostly because it signals that you don't take care of yourself. Unfortunately, I know many guys who need to learn HYGIENE. Brush your damn teeth.
I know a guy who isn't naturally very handsome at all in terms of face shape or anything, but the way he takes care of himself shows that he respects himself and that makes him attractive. It's not arrogance though. Just like, he makes sure his teeth are white and his clothes fit him well.
Personality: a guy who initially turns heads can suddenly become ugly if he says or does disgusting or mysogonistic things, or if he just acts like a loser (disloyal to his friends, boorish behavior, no ambition, etc.) A guy whose looks are less attention-grabbing at first but is warm, fun, and intelligent will be three times more handsome.
Also, there's a definite middle ground between acting like you're entitled to a woman's attention and coming off as desperate. We like men with confidence, like you show you're interested but not like your world will fall apart if we turn you down. On the other hand, I've had men mumble the most inane questions as though I owe them my attention (I don't know if that made sense to you).
Finally, DON'T BE A JERK. Don't lead us on and then act like we don't exist. It is very immature and hurtful. Don't lead on multiple women, that makes us feel very disrespected. If you turn someone down or break up with them, do it kindly and to their face and respect that they might be upset and/or have questions. Sending a text break-up and then pretending their subsequent emotions are a waste of your time is downright degrading. All of this stuff causes serious emotional trouble down the road because it affects our self-esteem and ability to trust. When you care about somebody, a friend or family member or boyfriend or teacher, then how they treat you and think of you has a much stronger impact than if a stranger were to act that way. So don't be a dick.
There's probably more, but really it all comes down to respect for both yourself and the other person. That goes for every relationship ever, romantic or not.