My game revolves around being direct. From the onset, I make it clear that I find the girl attractive and am interested in pursuing her sexually. That being said my texts usually reflect that. To avoid being needy my general rule of thumb is that if she stops responding first, then I wait at least 24 to 48 hours before texting her again. Furthermore, If I offer an invitation to hang out and she declines, usually 3 days up to 14 days.
Me: Haven't heard from you in a few days cutie. You do have a nice ass, but your losing points.
Her: Haha fuck. Sorry

what's up cutie?
Her: Send me a picture of you so I can save it hahaha
Me: [Send two picture], which one you like better?
Her: Haha I love them:) when are we going out?
Me: Thursday night once I finish my exams, send me a picture so I can take my mind of studying
Her: [Sexy picture of herself] That was from friday

Her: Good luck on your tests