There's no objective answer to that, but by collecting subjective answers you can probably spot patterns and something that might fit your own personality:
My subjective answer is:
be fit, not fat; not because you only control what you eat, but because you hit the gym. /r/Fitness is a great resource.
always dress for the occasion, if you're going out to dinner to a nice restaurant: elegant; to a bbq jeans and t-shirt is fine; both times show off your body in a tasteful manner thanks to #1 abobe
little make up to accentuate your natural feminine look
Be polite and courteous; not vulgar or rude.
Speak good English. "Gonna" "wanna" and too much foul language is not attractive. Part of #4 above.
When in company do NOT use your cell phone. If you are in the middle of a conversation and your phone rings do NOT pick up. Unless you have a job where you are on call for life or death emergency calls and that's your job calling, do not interrupt a conversation with anyone. Never. Part of #4 above.
Do what you say; and say what you mean. This is especially true when discussing boundaries of the relationship.
Fuck like a porn star in private, act like a lady in public; except when having sex in public places if you're both in to it.
Pay your own way on dates. No matter what he says. This is not 1915.
Be interesting. Cultivate your passions in life (fashion and gossips are not passions), and develop the career of your dreams, this is not 1915.
Be a good conversationalist: have something interesting to say (see #10 above), talk to contribute something of value to the conversation or shut the fuck up; when someone else is talking listen, and really listen. Don't monopolize or hijack the conversation; and if the conversation doesn't interests you, leave and pick another conversation with someone else.
There's more, but this is a good start.