Forget the Mylar Blankets and get yourself some Wool Blankets instead. They'll insulate and keep you warm even when wet. Mylar doesn't insulate, it just reflects infrared light. It's a nice supplement to a good sleeping bag, and great as a heat reflector inside a lean-to or on a windbreak opposite from you at a campfire, but they're no substitute for an actual blanket.

Otherwise, I would recommend the following:

1. Firesteel I have a Firesteel Armageddon and wouldn't trade it for the world, but the LMF is cheaper and gets great reviews as well.
2. Bahco Laplander One of the best purchases I've made.
3. Stainless Steel water bottle With this you can boil water to purify it, cook food and transport fluid.
4. 50' Paracord
5. Lifestraw
6. 4-Pack of Ponchos It sucks getting caught in the rain.
7. 8' X 10' Tarp Improvised shelter, wind break, etc.
8. Cotton Twine & Vaseline For making firestarters, tying up stuff and lots of other things.
9. Knot cards Because sometimes it's difficult to remember how to tie some knots correctly.
10. Emergency Whistles You'd be surprised how hard it is to yell for help when you're exhausted.
11. Lansky Puck sharpening stone. I have one and use it all the time. Just spit on it first, make sure you have the correct angle and move in small, slow circles.