With luggage restrictions, we try to pack as light as possible. If we can swing travellign in carryons, we always do ... which means packing as tight we can.
My preference is to roll everything (I've fit a full length dress) into zippy bags and squeeze out the air. Then all the airless bags get plopped into a suitcase.
Yes, everything comes out VERY wrinkled. I have a cheap $20 steamer from Walmart that works amazingly. It takes about 30 minutes or so, on the first day to steam all of our clothes and then we are set for the week.