Here's a couple tips I learned from some Alaskan River Guides who cannot cook without a Dutch Oven:
TIP 1) Put the higher number of coals on TOP of the D.O.(not the bottom)...since hot air rises, this will balance out the heat from top to bottom (equals around a 350 degree oven with the 20/10 coal ratio on the top/bottom of a large D.O., drop down to 10/5 with a small, 9" or aluminium D.O.) and basically gives you a much more consistent heat, top to bottom) and is less likely to have an under baked 'top'.
TIP 2) NEVER (!) open the D.O. while it is cooking...this will extend the bake time and give random results. Once you can smell whatever is cooking inside, it is done. This has never failed me. Combined with tip 1) above, I have never had something cooked in a D.O. turn out badly.
