Use a Divider
"If you're looking at your suitcase with all your heavy items in there, you don't want to put your pants on top of that because they're going to get wrinkled," McAlpin says. She recommends adding a divider – a placemat, piece of cardboard, or flat object – before putting in anything you plan on folding. The divider will also help with unpacking. "When you have that piece of cardboard in the center, you can reach in and take all your clothing out in one group."