Things you can do and carry to make a Searcher's job easier:
1) Tell people where you're going, when you'll be back. Leave them with a map if possible.
2) Don't go to the bar/casino/etc. after you're supposed to be back, without telling the appropriate people. (I'm serious!)
3) Give me a nice fat, muddy boot print by your truck.. let me see that tread, and the general direction of your travel.
4) For your ease and mine, use biodegradable flagging tape to mark your path in.. It'll help you get back out as well. You can buy it at most outdoor stores.. don't use the plastic stuff, it just makes the world less pretty. Remove the tape on your way out, even if it's bio-degradable... just make sure you're going the right way.
5) Take a compass bearing of your general direction of travel from your truck and leave it on a note on the dash. Check the bearing periodically. (Am I traveling towards that big mountain still? Yup, good). If you'd rather roam, that's fine.. the initial bearing is a big clue. Just say something on the note about wandering about. A note on this: Some people think it's a good idea to leave your time in/out information on a note here too... However it mostly seems as if it helps thieves know how long you'll be gone... leave that information with somebody you trust.
6) Carry signal devices, several. The no-pea whistles are my favorite audible device, they don't freeze up, and they carry forever. Mirrors are good, bright colors are wonderful, especially if you're laying down from injuries. Laser pointers are small and carry for a long while.. not a general purpose useful item.. but good anyway. Flashlights, strobes, etc.. just use your imagination.
7) Once you get to the point that you're lost or injured, make a mess.. Bend twigs, make it obvious that a human is in the area. Don't destroy the forest, but if you're in need.. you're in need.
8) Have any medications you need on you. If you're allergic to bee-stings, have your epi-pen or whatever you carry. Make sure the rescuers know if they have any special needs to deal with. We'll generally have some gear, but not all of us are medics, and specialized medicine might not be available.
9) If you start hearing people moving about near you, start a fuss. Blow your whistle flash the mirror and flashlight around, bang sticks together, whatever you can do.
That's just aside from the whole "Don't get lost" thing, and basic survival needs like a first aid kit.. By no means is this a comprehensive list, just some things off the top of my head that I've grown to appreciate.