Charismatic people get noticed through confidence, assertiveness, authority and presence. They are not arrogant at all but instead are noticed because the character of strength they project is directly attributive to their own unique inner character. If someone with a weak character tries to be charismatic they would more then likely fail as people would pick up on this congruency either sub-consciously or consciously and apply it to their mental framework i.e. they would treat the person as a weaker person opposed to the strong character they are projecting.
Just build up confidence and charisma will naturally follow. If you're living your life in purpose, in a job that inspires you to fulfill your passion and you have your sense of character, your emotions, your health and your wealth under control then people can't help but feel attracted to you.