RT -

Excellent question.

Take a simple piece (nursery tune)

Play it "by ear" (keep trying - if this is new - give it about half an hour -)

If the first part was a struggle let it rest and return later.

When you have the simple tune down....start on a new note/key

Work and work and work until you have performed the simple piece in 3 starting points/keys.

Let it rest.

Later, perform the three....which is best?

DO NOT gravitate to which is easiest....but which is BEST?

Sincerely,
Gargoyle

For me....Mulberry Bush/Monkey Weasle....is best in Eb