i'd go with a light application of foundation (mineral, if possible) but nothing very dewy or glowy (remember the dewy/glowy thing is generally more of a feminine look) and concealer if he's got any blemishes or bags under his eyes.
maybe use a matte bronzer (or MAC's natural MSFs if you have them) in the hollows of the cheeks and on the jawline to define the cheek and jaw bones. maybe a light application of MAC Tantone blush on the apples of the cheeks.
if he has dark hair, you can probably get away with black mascara, but i wouldn't suggest curling his lashes very much. maybe hold the curlers on for a couple seconds just to give them a little lift. if he's got blonde or light brown hair though, go with clear or blonde mascara. definately groow the brows and set them with MAC brow set (or clear mascara)
i second aeni's suggestion of a browbone highlight. but do this with caution (again, to avoid that dewy look) apply the highlighter with a VERY light hand
and then to top it all off, some lip balm and maybe a dab of Clear lipglass in the middle of the lips to draw attention to them
of course this, like flowerhead said, is all dependant on the shoot setting, theme, etc. but i HTH a little! good luck! and be sure to post pictures when you're done
