C.Z.
When I my children were little and we took long trips, I would pack an outfit, panties, socks, hair ties, everything but shoes in a ziplock baggie. That way, no problem when it came time to dress my kids, and all we had to find were the shoes. I also rolled their clothes as it seems to take up less room. Squeeze all the air out of the ziplock and you are ready to go! I also found that for wet/soiled clothes, it was very handy to have waterproof bags to store things in until I could get them washed.
I also packed jammies into one large bag and also stored their toothbrushes/toothpaste in the same bag. That way, when it is bedtime and time to brush teeth, everything is together.
I hope this helps!