Try using the conversation framework I use in my outer game guide along with sexual state:
chiefs-guide-to-outer-game-vt75887.html
...and tell us how it goes.
Everyone talks about degrees and subjects and all that boring crap. Sure, it can still be good for fluff talk and some shallow rapport, but you won't really peak anyone's interest with it unless there's already a good degree of sexual state being transfered between the two of you.
My impression is that you think being normal (boring) is enough to have a girl interested in you, and for her to maintain interest in you. That may work if you're good looking and she's actively looking for a date, but even a guy's looks are too varying of a variable. It's not enough to just have what you call "initial attraction." Always assume that you have initial attraction from the get-go and just get that "step" out of the way. Don't assume that most women are like most men when it comes to attraction; if a man is initially physically attracted to a woman, there's not much that can happen to change his level of attraction for her unless she suddenly gains a ton of weight. Just as volatile the rest of a woman's emotions can be, however, her attraction for someone may change as easily as New Orleans weather.