It varies, depending on the time of year and how long I plan to be on stand. Generally, though.....

Thermacell
Binos
Grunt tube
Flagging tape
Knife
Water
Snacks
Cell Phone (let's face it, you just NEVER know. After doing CPR on my best friend while fishing..I never leave home w/out it.)
2 way radio (if hunting w/ others)

That's really about it. I'm sure I'm forgetting something, but I travel light.