Personally I have a tripod that you can hang the dutchy from...ours has a chain that you can shorten to reduce heat...also used for the kettle as I don;t usually have a stove. This makes it into a normal(ish) saucepan/casserole. For baking I make a little pit to one side of the fire pit and place the dutchy over some glowing embers in the pit then place some on top...thus the oven bit of the dutch oven!
however you can rest the oven on stones at the edge of the fire pit to cook so long as you remember to turn the oven for even cooking.
as a good girl guide I have been known to fashion a suspendy thingy from branches (but you have to keep them wet or they burn...very inconvenient) I have also repurposed a BBQ grill and stood the dutchy on that (not so satisfactory as i couldn;t get to the fire!)
I'd go for the tripod usually...easiest and most stable!
I just build a sort of odd shaped cell thingy with rocks for my bonfire. A circle within a circle. The Dutch oven goes in the enclosed circle with the fire surrounding it. I'm really wary of tripods...I'm a bit of a klutz so quite sure I'd end up knocking it over but that may be due to the amount of wine consumed while cooking!