When we traveled with kids, I would leave the suitcase open in our bedroom about a month out and throw in items that would need to be more neatly organized later. Disney outfits they tended to wear at home would disappear into the suitcase after laundry. When they arrived they had all their fav Disney outfits. I had a cousin who always sent me hand-me-downs so all the Disney ones went into the suitcase. I do have a family picture with our youngest in a too large dress but she wanted to wear it. My fault for never really looking at it before packing.
For us, well, I'm always packed. After we return home and do laundry, shorts and tops that I only wear at WDW go back in the case. Then about a week out I tweak it depending on cruise wear or current promotions (mostly EPCOT festivals). DH packs the night or two before and he always forgets stuff = annoying.