I have multiple main characters, some male, some female. It all depends on the archtype or persona I have in mind when I create the character.
Sean - Young gungho captain who tends to get into trouble. Sort of a young Riker/mature Harry Kim hybrid.
Miranda - Imagined as one of the best doctors in Starfleet. So she's sort of based on Crusher and Pulaski.
T'Prenn - Based on the idea of Spock as a Science oriented captain, but I couldn't think of a good Vulcan male name so he became her. The only male name I could think of was Sypher, but I didn't like it.
Jason - A young Borg-liberated human with a deep hatred of the Borg. So I imagined him as a young, angsty/angry version of Locutus complete with bald head.