I always find it helpful to have an itemized list for packing. I have one list, that I keep as the orginial and I make a copy of it and add or delete as needed, to complete the list. This list is really great when packing not only for myself and husband, but also for my kids. I find that I never forget items this way.
I also love using ziploc bags to pack kids outfits. Put a whole outfit - shorts/shirts/underwear/socks in one bag. That way, the kids can just grab one thing out to get dressed in the mornings instead of shuffling through and messing up/unfolding everything. The bags are also nice to have on the trip home to carry wet/soiled items.