As a female (I'm in guy-mode to boot), I don't flirt first. I rely on the guy to flirt with me, since if he can't flirt with me then I don't want to risk being the fool in the social interaction (as a gay male, or transgender... can't afford that). Now, that doesn't put me off the market, it just makes things trickier.
Now, if the guy show me a slight interest, and I have a crush on him.... but really the first indicator he's into you is HIS EYES. You have to watch for this, since it's very subtle... a guy who is attracted to you; his pupils will enlarge. 99% of the guys whose eyes enlarge are attracted to me. Besides a lot of other things... he will want to touch you, more than the average person. He will find ways to spend time with you.
You really don't have to flirt, since a guy who likes you will like you for your looks. Looks mean everything to men. If you have the right look, you will get the guy. Opposites attract. Tall men=short women. Short men=tall women. Fat=skinny. Skinny=fat (like Anna Nicole).
Clothing wise; red, whites, and pinks (black if you're fat). Those are the 3 standards. Make it match too. High heels (3 inch). Perfumes; copulins; pheromones. Put on lipstick, and eyemake up... (as a guy.... yeah couldn't do this, but I bite my lips before meeting a guy I like/pinch my cheeks, and I dab a little mineral oil on my eyes, and then darken my eyebrows just a little bit). This works to overall feminize you. Wear simple necklace, never anything to take the attention from your own beauty.
Okay, flirting, use sexual indecency.... like have a blouse missing one button (exposing slight cleavage), or have a tear in your stockings, anything to hint to sex.
----
conversation wise.... too much work to talk about here,
read The Satanic Witch by Anton LaVey, book is a miracle for seduction (I had men fall in love with me with this book in minutes).
The Art of Seduction, by Robert Green is a good book too.
------------------
I don't look at any guy.... I don't flirt. I let my look speak for me. I don't flirt because I don't want people at work talking about me... I don't give anyone any reason to talk about me behind my back as far as being a whore.