Honestly, there is a million reasons why things didn't work out. They have a bf, they arent attracted to you, in a bad mood when met, didn't like where you placed your comma, etc. In end, you should never just improve to get some girl. That might be part of it, but you improve for yourself and yourself only.
This!
The key I have found is don't give them the opportunity to reject you and you won't even care..
-Won't give out number? Next
-"I have a bf" I laugh, smirk, and say "that's too bad"
-Send one casual text, no reply or long time to reply... next
-Flakes on a date? Don't go out of your way to set a date. Confirm beforehand if you have to... Have alternate plans
-Won't kiss close, I think
thanks for not wasting any more of my time... next
-"let's..." not see each any more or some BS... good luck to you!... next
It's easy when your not emotionally invested. It is also easy when you get more experience and realize how women are, fickle emotional creatures. Her words mean something the moment they come out of her mouth, not much longer than that!