On trek we had a different color for each family, the trek staff, and the other adults. We purchased our bandanas from Tan's Club for a real good price. Click here to see a picture of a bandana.
We also printed a journal for each person that went on trek. We took the one from Handcart-trek.org and modified it for our purposes.
There are many wonderful resources that list essential first aid kit elements. There are a few things that the lists do not itemize that we discovered that were being desired, were stomach ailment remedies.