I seem to make characters with skillsets that make them into leaders, rather than being proactively choosing to take on the role itself.
Frequently my characters tend to have a more "outdoors" skillset, and a broader skillset than most other characters they interact with, because I tend to try and make my characters realistic. an example would be my character from a "mutant school" game, who was fifteen years old, but came from a very remote town. He knew a lot of outdoor skills: hunting, fishing, bushcraft, survivalism, etc. At the same time, he played sports, and he knew how to make music on a computer. He read books even. Most people who make a character period, focus on giving their character a handful of "skillsets", rather than fleshing them out like a real bloody person (How many "survivalism" games have the typical "Soldier" thrown in?). It seems as though because my characters have a broad knowledge base, and a grounded mentality, that other people's characters instinctively follow them (even if I try to make them non-leaders).
In a current game, my character is sort of turning into one of the "leaders" of the game, just because of his history, experience, and personality. He might be sort of a father-figure to one, or a couple other people in the game, because he is older and more experienced. One of the other character's even asked him to be the leader of his group, but my character turned him down, because he doesn't want to be a leader. Even though he very likely will end up being put into the position of a third group in the game with the way things are working out.