Guys in good shape should feel free to go for broke with patterns and colors, says Toll. Anything that will give him an opportunity to express his individuality. The danger of a too-low vest is that it can sometimes look like a belly sling. For a shorter man, a peaked tuxedo lapel is a godsend-it'll make the body look longer, since it draws the eye up and out. But it looks good on tall guys, too.
Shawl collars can be tricky, depending on the width of the collar itself.
Trust your eye-or the eye of the guy at your tux shop. Try a lay-down collar instead. Visit Local Resources for Formalwear vendors in your area.