Training on CPR, first aid and outdoor emergency care. Go through first aid kit to ensure it's not expired and know how to use it. Reminds me that I need go through my MyMedic kit and review my OEC book....thanks for the reminder!
Extra gloves, hats and socks. Not all of us are blessed with a full head of hair and beard.
Cell phone cables for android and iphone to not only charge your phone, but another stranded person's phone. Big challenge is communication and navigation. I also download Google offline maps for any area offroading or where I may lose signal.
Jumper cables, esp one of those USB battery jump boxes.