Is there a way to go about things to get someone to fancy you again ?

Yes leave her alone and let her make up her own mind.

It depends on if you did something that made her go off you.. A girl doesn't want a guy constantly talking to her 24/7 she WILL get bored, just talk to her sometimes, let her know your there for her and if she opens up to you just tell hr there's always a space left in your heart for her :)

Hope I helped xxx

Give her space and do your thing. If she misses you - she'll contact you. Good luck.