Tom Cruise is only 3 inches taller than you. That's nothing. They've even developed certain filming techniques to make him appear taller and more heroic in his movies. Obviously, one of these is not putting him next to tall men in the same shot. You see where I'm going with this...
When approaching/isolating, be sure you're a good measure away from your tall male friends, and NEVER justify or defend your height, because you're then acknowledging that it's a flaw (it isn't!)
I also don't like your "I'm big where it counts" retort. It's canned, cliched and oversexual. Instead, play with her. Pick a short girl:
"Hi, I'm [blah]"
"You're not very big"
"That's because I'm not wearing heels tonight, like you. Kick those off you cheater, and come here"