I'm confuse. The subject says how to reconcile with a girl, but your message is how to surprise one. So let's start with reconciling with a girl. Talking it out is great. Voice out your side, and hear and understand her side. After that if you guys are still angry with each other give each other space. Always think about this, is winning an argument more important that your relationship with her. Next, the surprise part is easy. Start with being consistent at something, then after sometime break it.