I do it this way: pants layed out folded in half (knees touching, not ankles/waist) and then lay the shirt on top of that, again folded in half (at the buttons). I then put an undershirt and boxers/socks at the bottom of the pants and do one big roll-up. Stick that in a plastic bag and voila! you have less wrinkles than if you had driven to work.
I have found that the underwear at the bottom of the pants (and therefore, the center of the roll) is essential to making sure your shirt doesn't get wrinkled. It creates a bit of a core for everything to roll onto, which decreases wrinkles at the bottom of the shirt...even though that part ends up tucked in anyway.
I can post pictures and diagrams if a more detailed how-to is requested.
