So after going to concert last night, and approaching three separate girls, I have realized I am an awful judge of age.

I am a college sophomore and nineteen years old so kind of feel like I am in a middle ground when it comes to approaching. For example, the first girl I approached, I was thinking would be freshmen or sophomore in college, she was a freshmen in high school, so I noped out of there. The second girl I approached, looked at me and said,"Nice try kid." The third was a sophomore in high school.

How can I better judge the age of women in a venue for like a concert so I don't approach girls so much younger than me? Any tips or tricks?