We used to pack in laundry baskets until we outgrew them. We've graduated to Rubbermaid 20 gallon totes, but the general principal is the same.
For each day, everyones' outfit goes into a tote. Toiletries, swim suits, and jammies are in a separate tote. When we arrive at a hotel, we just take in the next day's tote and the swim/jammie tote (classy visual, right?). We take out the clean clothes and then use the empty tote as a hamper. When we need to do laundry (on the road or back at home), we just pull the dirties from the tote and wash, wash, wash.
We also have a tote for our food and snacks. They stack so much better than individual suitcases and bags.
As I'm packing I keep what I call "The List of Ommisions." This contains the items that haven't been packed yet broken down by tote. As we hunt down the missing articles, we cross them off the list.