The Ten Essentials, when heading for the woods, are the ten things you need to have with you at all times for safety. If you're hiking or camping, they're the necessities that belong in your day pack. If you're on a backpacking trip, you will have them, and if you venture off away from your campsite for exploring, you will take them along for the day.
Everybody tweaks the list a little according to thier needs, but the basics are all there, this is my version. Check out the list, and if there's anything you're missing, start adding supplies so you are ready for the Summer. The gear you already have can be taken out and examined. Put new batteries in headlamps and flashlights, inspect everything and make sure it's in good working order for this Summer's adventures.
1. Water and Food: Carry a full Nalgene style bottle along with your hydration system. A Steri-Pen or purification device is also great to have along for the back country. Extra bars, granola, etc.
2. Navigation: Compass and map, even if you have a GPS.
3. Clothing: You should have extra layers for warmth and something for rain. If you're wearing shorts, take long pants or wear convertible pants.
4. Communication device: Cell phone and/or emergency location device and whistle.
5. Light: Headlamp or flashlight (I prefer a headlamp for hands free light).
6. First Aid Kit: I have personalized my kit with migraine meds and kid's meds. Take a small kit, but make sure it has what you need.
7. Fire: Matches, fire starter, lighter.
8. Knife or Multi-tool
9. Shelter: An emergency bivy sack, tarp, or blanket.
10. Sun Protection: Sun glasses, sunscreen, lip balm, hat.
Image Credit: GuideGunner