I really want to get good at flirting but there is one barrier I have to overcome. I am just straight up scared to try. I usually make the excuse that "oh it doesn't come naturally to me, its not in my personality" but honestly I think the real reason is that I am just too scared.

It's scary because flirting has such a thin margin of error, there is only a small gap between you just being too safe/platonic and one being creepy. It differs woman to woman, and it differs based on how attracted she is to you. I believe I am below average looks wise, so I am scared that it will blow up in my face more times than not. I wish a simple "no" was the worst that could happen, but a "wtf are you doing" is even worse and I would hate for that to happen, especially since I have never tried flirting before. A bad flirt has the potential to ruin an interaction and even ruin my current relationship to the person I am talking to.

Any tips to get over it or is it natural for it to be scary?