How to start talking to a girl I like?

Typically I’m not someone the girls tend to go for I’m last choice in my friend group. I’m not weird or anything like that but I wouldn’t say I’m the best looking maybe like 4. But in the past I’ve tried chatting to girls who I like who aren’t necessarily way out of my league but they tend to just ignore me or send it to their friends and laugh.

I’ve had 2 cases as well where I’ve been talking but they say they can’t anymore because they think of me like a friend. so how can I approach these girls so I don’t get shut out and when I do how do I keep things on the right track?

Any suggestions from m or f would be interesting to see what each gender has for advice. Thanks guys :)