Mxsmanic wrote:
What aspects of slow-speed or minimum-speed flight should I practice?

I've managed to fly for indefinite periods at just above stall speed, straight
and level and in standard-rate turns, holding altitude steady. I've managed
to do this both with full flaps and no flaps, gear extended and retracted.
What things should I try at these low speeds? The aircraft (Baron 58, in this
case) seems very unstable at low speeds.

In slow flight, you should limit your bank angle to 10 deg. Practice
left and right 90 degree turns, hold altitude within 20 feet. Keep
the ball centered at all times.

If I am flying by hand, how well should I be able to hold altitude in level
flight? I'm not talking about regulatory restrictions, I'm talking about how
well a decent pilot should be able to do this. Within 100 feet? Fifty feet?
Five feet? And I mean without trimming first. What about when making a turn?

How steeply should I be able to turn coordinated and without losing altitude?
I can do standard turns well enough, but how much steeper do I have to go?

First, do alternating left and right 360 turns at 45 degree bank
without losing or gaining more than 100 feet. Roll out precisely on
your original heading. Then practice until you can do +/- 50 feet.