A good long fire is great for cooking and spewing out heat. This one was used when I was sleeping in a lean to shelter in the week long woodland ways course and the heat was needed to be able to sleep without a sleeping bag (as was the aim of the week).
I tried the upside down fire a while back as there was a pretty good source of fuel. Worked a charm, kept me warm into the evening and took no maintenance burning with flames for a good 3 hours. It provides an excellent bed of embers to anneal a file knife I was making. The embers would also be great for cooking on.
A small "standard" fire with fuel the thickness of your thumb is all you need for a simple meal and a brew. Ideal for a cheeky overnighter.
If I'm not setting up camp, or open fires are a no-no or I want to use minimal fuel then the good old hobo stove/ honey stove/emberlit is order of the day. Still something very satisfying to have fire over gas/liquid fuel.
I've been meaning to try a Dakota fire pit too, as it seems a very economical (and stealthy) option.