Just like many teenagers, I spent my puberty with very low self esteem. I’m a university student now and although I do feel insecure sometimes, it’s gotten much better. Here are my personal tips on gaining your self confidence.
First is to dress well. You might think that’s lookism, but what I mean by “dress well” is not about having to look flawless all the time. Wearing your favorite shirt, favorite color of lipstick or anything that makes you feel happier. These things become a shield to protect you and be brave.
Second is to focus on things you like to do. The happiest time of the day is when we’re doing our hobbies. It’s less stressful to work hard on things you enjoy than things you don’t. If you make effort on a certain thing, it might actually turn into one of your life accomplishments. For me, it was language learning.
Third is to accept yourself being insecure. That seems like an opposing idea, but always forcing yourself to act and think in a certain image can be very tiring. Confidence starts with accepting your weaknesses. In that way you are ready to be stronger.

Of course, my self esteem isn’t 100% yet and it’s probably almost impossible to reach that level. However, I am hopeful that I’ll find my self in a better mental position in the future.