I find these components to be most useful, and customized to my needs. you may wish to change a few things. I feel also that this is better than most commercially available ones. that said you could use a fair few of the things that come in those. and this is also just an opinion, so don't blame me if you get into trouble and it doesn't work for you.
it worked for me when i got lost in the new forest, which is a huge field and woodland area. in the end we walked our way out. 40 miles in 2 days. this kit worked for me so i thought i would share.
Step 1: The First Thing May Be the Hardest Thing to Get!
that said once you have one your in business so to speak. i have photos of most things how ever not all of them, but i shall right them down as well. and i shall explain how to use these things, and my reasoning for including them. and what to do with them in the field.
Step 2: What Goes in It
needles and thread
pencil (half of one or one of those small ikea ones that everyone steals)
broken up CD.
fire steels. (light my fire ones are best)
variety of hooks.
things not pictured - because either I don't have or couldn't be bothered to go and find.
water purification tablets, a good idea
condoms - 2 or three should do. (not incase you get lucky!)
Step 3: Pack It All Down.
Step 4: Uses for Various Things and Stuff That You Might Have Expected to See There But Aren't.
how ever you may be curious as to the use of the condom (try to get the ones with out spermicide in if you can help it, some of them taste funny) - your not going to be too worried about getting laid i imagine. they have a great many uses. the first one being that they can be used to collect and carry water in. they keep stuff dry, matches and so forth. they can help to keep wounds clean. and they really do pack small.
tampons, did i lose my mind? no fear not dear reader. you see they come sealed and sterile. and because of what they are meant to do, they absorb blood really rather well, thus they make great dressings for semi - serious cuts. also they are easy to ignite with fire steels.
the broken CD is actually very useful as a Signaling mirror.
Step 5: Why I Don't Carry an Emergancy Compass.
always remember (its very useful) that the sun rises in the east and sets in the west.
(i smell an instructable coming on how to find north with out a compass)
with the cotton needle and magnet you can make a compass, the advantage is you can also stitch things together.
what you do is rub the magnet against the needle. when you do this tough do it point to eye, then take it off the magnet and repeat. if you do it in two different directions it will not work. to check if it has worked take another metal object that is attracted to the magnet but not itself a magnet, say your penknife and see if the needle now acts as a magnet, it it does then you've done this right.
now hang it from the cotton and a tree, it will point northwards, it is exactly the same as my hiking compass so its perfectly good enough.