Charisma is not an innate talent.
Like most things in life, it's something we can develop by putting in work. Whenever I speak to teenagers, charisma is something they're desperate to create. In your teens, 'climbing the social hierarchy' and 'finding a mate' are high on your priority list. Charisma helps with this.
Now, the problem with charisma is that you don't personally define whether you're charismatic. It's others that define if you're charismatic. In principle, developing charisma means developing influence. Therefore, you're only charismatic if you're able to create influence.
But, if you put a gun to my head and asked me, "what are the most important characteristics for a charismatic person" then here's what I'd say.
1) They Smile Often
Smiling is contagious. If you smile at others, they'll perceive you as more confident, and in general, they'll want to spend more time with you.
2) They Ask Questions
People love talking about themselves. If you ask people questions, they'll begin to open up to you. Remember, the most exciting topic people have to talk about is themselves. So let them talk.
3) They Listen Deeply
When someone is talking, a charismatic person listens to what they have to say. They then use what the other person is saying as a springboard to further the conversation.
4) They Believe They're Charismatic
Think it and you will become it. This phrase is cliché for a reason. When you believe you're charismatic, your voice will deepen, your sentences will become more concise, and you'll stand in a much more powerful way.
5) They Have Presence
Presence is a fancy way of saying that others know when you're in the room. They can sense it. They can see it. They can hear it. Developing presence comes from confidence, self-belief and a little practice.
A Lesson for Future Champions
Charisma is necessary for leadership. It's rare to find leaders that cannot influence others. Unless you come from an influential family or financial situation, crafting charisma is your best option to create influence.
The above list is not exhaustive. There are other ways to develop charisma. However, I'd like to believe that the above list is the simplest way with the least amount of effort. It's possible for anyone reading this to develop these characteristics and take these actions.
Charisma will help you get what you want. It will help get people on your side. It will help rally people toward a cause.
In life, you're rarely a one-person army, developing charisma will help you find people that will invest in your success.