Choose all of the clothing, accessories, shoes and toiletries you plan to bring and lay them out. Put anything back that isn't a necessity and try to limit shoes to two or three pairs. Pack travel-sized toiletries whenever possible to minimize baggage weight and maximize space.
Roll casual clothing like knits, jeans and pajamas and place them in the suitcase. Shoes can be inserted around the edges of the suitcase wherever there is room, along with your toiletry bag. Stuff socks inside of shoes.
Utilize the interior zippered pockets of your suitcase, if you have them, to stow underwear, scarves and additional accessories. Otherwise toss these in a lingerie bag and place it along the edges of the suitcase or in between rolled clothing.
Fold dress shirts and place them on top of the rolled up items, then lay dresses, skirts or dress pants along the top of the folded pieces. Pack delicate or wrinkle-prone items in plastic dry cleaning bags on hangers and drape them along the top of the pile.
Check your airline's baggage weight restrictions and weigh your bag before leaving. If your bag is too heavy, remove items and re-weigh it until your bag meets the guidelines.