Assume all skillets are properly seasoned.

I have a collection of cast iron skillets ranging in size from ~9" to
~24".

Thinking I was going to duplicate the flat surface resturants use for
hamburgers, pancakes, almost everything, I took down the 24" dropped
some butter in the center and turned the heat on med-low. Then I began
the think about the heat distribution.

Obviously the flame (gas stove) doesn't evenly cover the bottom of
the skillet. If I turn the stove to high, the part of the skillet over
the flame will get very hot (and hurt the seasoning) before the other
parts of the skillet get warm. So, there must be a process to get the
skillet uniformly hot and not burn the seasoning or clarify the
butter.

I'm thinking the process might be : cold skillet placed over med. low
heat until the heat has spread uniformly over the skillet. Add butter
or oil, begin saute or whatever.

Anyone have a process they'd care to share? - Mike