Need advice on improving my attitude?

I always had a problem with projecting the correct attitude towards the girl I'm interested in giving them the wrong impression that I'm not interested in her, any advice on how to improve myself? Physical, mentally, verbally?

Updates
10 mo
Usually, I won't have a problem with the girl not interested in me.
It's the girl that is interested in me that I have a problem with.
Ok, I'm a bit strange.
Need advice on improving my attitude?
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