Three options. All are "easy" using hemostats or crochet hooks in the "K" through "L" size range, all eat up an incredible amount of cordage, and all can be unraveled by undoing a few loops and pulling on the running end:

1) Double Chain Sinnet, also called a Bugler's Braid. Works best with homestats. Attach it to the first buckle half (2 piece sidelock buckle) in step 4 by running the new bight through the strap loop on the buckle before running it through the previous bight.

http://www.free-macrame-patterns.com/bugle-braid.html

To finish it, pass the next to last bight through stap loop on the second buckle half, the pass the final bight and running end of the cord through it before tightening it down. Tie off the running end with a bulky stopper knot (oysterman's or double overhand) and/or a toggle bead.

2) Crochet. No I'm not kidding, it is very easy to crochet paracord. A single crochet stitch produces the tightest pattern and have the least give, and a triple crochet stitch will cover the greatest area and be the 'stretchiest'. These are the basic instructions, but a video tutorial would be better. You will have to get creative to attach them to the buckles.

http://www.crochetspot.com/how-to-crochet-single-crochet-stitches-sc/
http://www.crochetspot.com/how-to-crochet-double-crochet-stitches-dc/
http://www.crochetspot.com/how-to-crochet-treble-crochet-stitches-tr/

3) Slatt's rescue belt. No preference to hemostats or crochet hooks. Unholy pain to dress the knot.

http://www.orionn49.com/slatts_rescue_belt_knot1.htm

There are a lot more patterns, but these are the three that I think are best suited for a 'survival' bracelet.