I don't yet have one but would assume it is the same as all BBQ
I always wait until the dirty smoke is gone before I even consider adding food. White smoke = bad taste to meat
also depends on what you are cooking...
Low and slow you really want a stable temperature so that you do not spike. Many heat soak a kamado before they cook at this temp. This will allow for the grill to heat up to a stable rock solid temp, avoiding sudden spikes or drops once you add your food.
I always try and get my temp solid for at least 15 min, that way I know the temp is going to be pretty consistent throughout duration of the cook