The first red headed fantasy hero I remember is Tarl Cabot, from a horrible series of books called Gor that I read as a child. Don't read them, please. But the particular paperback editions I had had decent cover art (google image search "Tarnsman of Gor" ) and Cabot looked like a pretty badass warrior. So really whenever I picture Rand I picture Cabot.

Unfortunately Cabot suffered from Fantasy Hero Bodybuilder Loincloth Syndrome even though he was a professor. So instead of picturing Rand as late-teens farmboy, albeit one with shoulders an axe-handle across, I've got him as a bodybuilder like the Gor cover art. Thanks to Darrel K. Sweet, I also sometimes can't help picturing him as a disproportionate mutant with unlikely clothing. ACoS muscle shirt, anybody?

One way to picture Rand as a more likely badass is to remember he's half Aiel, and they're as badass as it gets.