How to be confident
Fake it until you make it
If you have low self esteem or you feel worthless you really need to change something in your attitude. Everybody has value which is unique and what others don't have. Try to find your good charasteristics, write them down and read them every day. Try to act like if you would be the most confident man or woman in the world and you will start to notice that you are becoming what you are thinking about the most. So fake it until you make it.
Learn how confident people behave
Just wath other confident people and try to imitate their behaviour. Learn how they walk, what posture they have most of the time, what their habits are. If you imitate those things your confidence level will be increased.
Make eye contact
If you speak with somebody don't look at the floor, always try to make eye contact because it helps you to feel more confidence. The other good thing is that the other person will also beleive that you are confident even if you are not.
Find something what you are good in
If you realize that you have something what you are good in you will always have confidence while you do that. It can be a hobby or anything else but if you can master it you will know that if you can feel confidence in one part of life maybe you can feel it in other parts of your life too. Try to always bring that feeling of confidence to other areas of your life.