Don't "NC" her, don't "backburner" her, just stop talking to her and move on. NC is when you're still trying to play games with her and use "tactics", total bunk... Just move the **** on with your life and ask out another girl.
Most guys accidentally kill attraction before they even speak. They assume they need a bigger bank account, a better physique, or smoother lines. They miss the point.
Female desire operates on a specific set of psychological triggers. Break them, and you're invisible. Follow them, and you become magnetic.
I learned this the hard way. Years of freezing up. Getting friend-zoned. Watching other guys walk away with the girl I wanted. Then I discovered a set of 22 simple rules that rewired my entire approach.