What you could do to keep her wanting more is if the date is going really well,then cut it off early. The better the date goes,the sooner you should end it. Kind of like watching a tv show that you're really into,where things are intriguing and interesting,and just when something exciting is about to happen and you're on the edge of you seat,the show goes off.
Also,that idea about whether or not to text her back if she text you saying that she had a good time,you can ignore it if you want,however,if I were you instead of ignoring it,I would send her a text back saying,"Well,if you think that was fun,wait until you see what I have planned for you next time"
Of course,she's going to ask you what it is,but don't tell her. Keep her in suspense. This way she won't be able to wait to see you again.
As for what the "exciting" thing is you have planned,I'm sure you can come up with something.