I usually take a while to answer... give it like 15, 20 minutes. It shows that at the end of the date, you didnt spend all your time wondering about her... your a busy guy!
When I finally do answer, I make sure its something cocky, funny and will make her smile.
If she texts you with something like "Heyy I had a great time!"
Answer with either an inside joke you had on that date, tease her about an embarrassing moment, or just be cocky!
Once a girl said "It was great meeting you

"
I answered "Obviously it is! I bet your feeling the butterflies right now, just dont go falling in love with me! Il break your heart!

"
Shel most probably reply something along the lines of: Yaaa right, lol your falling in love with ME!
and there you go, you have a conversation AND you can tease her about it next date.
-Legacy