You've got to start by buying a full-packer brisket. That's the big cryovac bagged ones that run anywhere from 1.39/lb to 2.59/lb depending where you are in the US.
Separate the point from the flat (the point is the thick torpedo shaped end, the flat, the other thinner end). This link will show you how to do it.http://www.ilbbqs.com/brisket/
The point is what turns into burnt ends.
Rub that puppy. Barbecue it low and slow over wood, and here is where 225 F smoking temps really pay off. Once it gets 185 F bring it inside, put it in a pan, add 1/4 cup apple juice, foil it tightly and stick it in a cold oven or cooler (no ice) for an hour or so.
Bring it out, cut it up into chunks about 1 to 2" cubed. Put back into the pan, slather in BBQ sauce and mix well, then put back into the smoker for another 3 hours or so. They will dry out, get darker and delicious!
After that you have burnt ends!
If you have any questions, just shoot me a PM i'll be glad to help you out.