If sorcery requires many materials and foci, then that would seem to encourage a lot of pockets; hence jackets and coats. I also note that the 'stereotypical' wizard is often attired in garments that bear glyphs and runes of some significance. So now we're talking about jackets and other pieces that are heavily decorated, with a lot of flair.
Furthermore, depending on the type of magic, jewelry and tattoos may also play a large role. Tattoos nowadays aren't even unusual so there's no reason for wizards to need to hide them, except perhaps from people who might understand their true significance.
So we're looking for people who are heavily tatted and pierced, with layers of clothes that can conceal items and/or are covered with mystic runes or talismans. Which to me means bikers, punk rockers, possibly gangbangers, or perhaps hipster douchebags.
You're welcome.
Oh, and in about six years when grunge comes back, that look will fit in pretty well too.