Zp it up. Add any of the things you might need in flight to the outside pockets, or keep that stuff in a small bag that you will slide under your seat...
If you are like me, you do more than your share of travel. Business conferences, etc... Lots of places where you ahve to spend a couple days in khakis and collared shirts, and maybe a sport coat. Life is so much easier if you can fit all your stuff into a carry on. Using this technique maximizes space an minimizes (but does not prevent) wrinkles. You may need to touch up with an iron in the hotel room.
Notice that we start outside the suitcase. Lay out your shirts flat as you can, one on top of each other on a flat surface, such as your bed. Button any shirt all the way up and make sure the collar is not folded funny.
Step 2: Lay ou the Pants
Lay the pants as Illustrated in the picture, with the waist of the pants aligned with one shoulder of the shirt and extending out along the other sleeve. Pants should be folded in half according to whether or not you want to maintain a crease.
Alternate the alignement of the waist bands so that the pant legs extend along each sleeve.
Step 3: Add Socks and unmentionables
With all your pants and shirts in place, lay out your underwear nice and flat on the pile. Also, un couple your socks and lay them out flat next to each other on top of the underwear. The idea is to make a solid, flat stack of clothing roughly from shoulder to shoulder to mid torso of the first shirt you layed out.