I would consider throwing in some sort of blister remedy -- moleskin, spyroflex, Compeed/Band-Aid Blister Block (my personal favorite). It seems like that's the most common reason I dive into the first aid kit. Some other things to consider: cortisone cream, EMT shears, emergency dental kit to replace a lost filling/crown (if anyone in your family has dental work), cough drops/sore throat lozenges, cold medicine, instant cold pack, eye drops/eye wash.