You know, for me, it's always worked. it makes YOU in charge of where the relationship goes, and HER having to wait on YOU to move forward or not. nothing empowers you more than being the first to claim her as your friend, not the otherway around. let her do it first, and she has you in her grasp. dangerous, if you ask me.
I even like to talk about my standards, and say how "I'll like sex, but I won't have sex with just ANY girl...I want to find a girl who'll meet my expectations, as I have VERY high standards, that aren't easily satisfied by the common woman" and you do that, you'll make yourself the prize, and her want you, not vice versa.
trust me, 90% of my sexual conquests were done this way. all my gfs started out as girls I (repeat: me, myself) placed in the friendzone. I was never placed there, because I'd be the placer, not the placee. it drives them nuts and makes them want you more because you're seen as unattainable--it's great for getting girls to lust over you, as she'll probably tell her friends how much she wants you, and thus drive other girls to want you to. Everyone wins!