Next time don't send ANY post date texts for at least 3-4 days unless she contacts you first. At the end of the date say something to the effect of "I had fun" (if you really did) and don't promise you'll contact her, or ask her to go out again. You want her to be wondering where she stands with you. By her starting to obsess over this her attraction will naturally grow.
If she contacts you at any point after the date (before you contact her 3-4 days later) assume that she's indirectly saying "hey, take the hint and ask me out again!" and quickly set up the second date.
If she contacts you at any point after the date (before you contact her 3-4 days later) assume that she's indirectly saying "hey, take the hint and ask me out again!" and quickly set up the second date.