A few band-aids, blister pads or moleskins, a pair of tweezers. Travel stores often carry prepacked kits, but you can put a small one together and put the items in a ziploc bag. This should include your passport, a photocopy of your passport identification page, a set of two passport photos, your unused plane tickets, your itinerary. You should not stash money in this because that should be kept next to your skin in a secret money holder. You can use a regular envelope for this, or a slightly larger booklet-sized envelope that can hold some bulk.
Many passport photos come in pop-up holders.
A twist tie helps keeps cables together as well. If you don't have a bag for this, stick it in a clean sock. As discussed in the Clothing Tips section of the FAQ, you could use a number of various packs to store your clothes. Something I do and that has worked very well is to have my travelpack filled and practically ready to go. The only items I need to add are a few articles of clothing, reading materials, and vital documents.