It depends on your waist size, because this will have a big impact on the hem size for a given cut of jean (tapered vs. straight vs. bootcut). In my opinion hems under 7.5" -- which are common in tapered jeans in a 30 or smaller waist size -- don't tend to look good with any shoes except possibly Chucks. If you want to wear jeans with dress shoes -- for example, somewhat chunky AE brogues -- I'd suggest looking for a hem of 7.5-8" (or maybe even 8.5", depending your foot size). That may mean a taper or a straight cut depending on your waist size. Some guys do manage to pull off the tiny-hem-floating-atop-dress-shoes look, but it's no good for most of us. Especially if you're of average height or shorter, your feet will end up looking big and awkward, and too much attention will be drawn to your ankles.