Disclaimer: I'm not a PUA or even close. In fact I still have trouble with AA but I'm working on it and often analyze things after they happened which lead me to this method:

TL;DR Got a wrong number from a girl when you botched the first approach but know you can do better? Approach her again and tell her you accidentally deleted her number. Almost like starting from a clean slate!

Story: I go to a university and that's where I get more if not all of my interaction with girls. I haven't really tried to approach any girl since the end of last semester (Dec 5) so I was extremely out of of practice and felt myself go back to my first approach with all the negative thoughts. I did see this girl I was interested in approaching for a few days around school. I saw her a lot. Turns out, she has the same breaks from classes as me. One day while walking around with my friends I noticed her and 2 friends sitting by some tables. I decided to go and approach and it SUCKED! I blanked, just asked for her number, didn't introduce myself, left an awkward silence as she was putting her number in, and then just left. Turns out the number was a fake number. I wasn't happy with that though because I knew I was better than that embarrassment. So here's what I did the next day I saw her at school:

Method:

So I realized I saw her and botched the first attempt and before my negative side could kick in I quickly approached her, with the same 2 friends, and and put my hand on her shoulder and just acted like I knew everyone. I asked how they were doing and told her I was sorry for not texting her and that I accidentally deleted her number and wanted to know if she could give it to me again. So she starts putting it in my phone but don't let the same mistake happen twice. I'm a lot more collected, a lot more charming and actually included her friends and told them I wanted to take their friend for a quick coffee right then and they should help peer pressure me into it. They help me out and what was one an EPIC fail turned out pretty good.

I'm not sure if this will always work but it worked for me this once. Hope you guys can try it and let me know if you get the same results!