I have been using burlap potato sacks for the last few years. They seem to
last a long time and give a fairly cool smoke. You cut them into strips
about a foot wide , fold into three and roll them up into a bundle that
fits into your smoker. I get them from the local potato growers co-op for
about $.25 each.
 
Previously, I used planer shavings with good success. The sacks are less
messy, burn longer, and produce less waste. After use, I dump the
remaining burlap into a (clean) paint can and put on the lid. The remnants
can be used to start the smoker next time.
 
 
Donald Aitken
11710-129 Street
Edmonton Alberta Canada
T5M 0Y7