I think you could pull that off ... :P
could you assist - lol
you gotta add great clothes to make the beret stand out. You could have it slightly on your head
Shave your head and grow a stache.
You have to wear it until it becomes something everyone associates with you. Jamie from Mythbusters can't pull a beret off any better than anyone else, it's a ridiculous hat. But he's worn it so long that people see it as "him."
Get a cane too!!
Jamie would have to take precautions if he is going to pull off Beret