Here's my two cents as a guy who's now considered well above average (used to be below average.)

-Being born attractive is both an advantage and a disadvantage. Attractive people get their way in life easier and that is a psychological fact. People tend to act friendly if they think you are attractive. BUT for the same reason 10/10 people are usually 'dumb' or 'peaked in high school' because they tend to think they don't need to improve themselves in other aspects of life. And when they realize this (when looks start to deprive) it is too late as their teenage years or even twenties are gone.

-You can increase your attractiveness by a TON but there is a catch (wait for it).
1- workout: better health, better looks, sense of achievement, and progress = leads to more confidence. Also, I am assuming you would like a hot partner. They probably do too.

2-Improve yourself in different aspects of life. Academy, career, sense of humor, sports... etc. Go to events, watch films, have a broad taste in music. Find what you like in life. I know it is hard to have hobbies while trying to survive. That is the reason you must find the things you genuinely ENJOY. If you try to do these just to get it on with people, you will most definitely fail.

3- Develop a sense of style. Learn how to trim your beard/do your make-up, how to style your hair, wear something other than airforce 1's this is not military and you are not obliged to wear a uniform. I should not need to mention this but I will. especially for men; personal hygiene. Brush your teeth, use a deodorant and perfume, shower every day. Smelling good is definitely a turn-on and vice versa.

4-Know the difference between confidence and delusion. Be confident but have reasons for it. If you lack in everything that I mention above and you are still 'confident'; you are just delusional. If you don't pay attention to yourself and still expect others to do so, you won't be satisfied with the result.

If you combine all of these (as much as you can) you will know yourself, your limits, what suits you and what doesn't. You will have some conversation pieces from your experiences, hobbies. Therefore, you will be overall more interesting and most probably confident/charismatic.

Now the catch: If you try to follow this advice with the sole motivation of getting laid: you will fail at some point.
All of these are required in order to take care of yourself and enjoy life to the fullest. And this is from my personal experience. I have failed. Then, succeeded. Best of luck.