Nobody has mentioned the microwave. I hesitate to because I'm such a
newbie my ideas change from day to day. But I have been zapping almost
all of my bowls and vessels and all are turned very green. If they are
turned to a uniform thickness and fairly thin (1/4" or less) then I
get very little warping or cracking. The only bad cracking I've had is
when I turned end grain, with the pith in, and left the base thick. I
guess that's an invitation for problems no matter what you do.

If you want a perfect bowl, turn to about 1/2", zap, then re-turn.

I've found that anything much thicker than 1/2'' just doesn't get dry
in the middle no matter how much you zap.

I use O'Donnel's method--4 min. at 40%, wait to cool, then repeat. At
1/8 to 1/4 inch it takes 4-6 cycles. 1/2 takes a whole bunch of
cycles.

Earl