At the risk of sounding like an expert, I'll pass on a few of my secrets
for good pumping.  First, it helps to be able to read what's about to
come up on the roll, or to have in mind how you want the music to sound.

The next point is to ignore the famous someone who once said, "The most
important thing is to pump evenly."  Many of my friends who own players
pump hard and evenly.  They are loud, badly loud.  It is necessarily to
learn to pump gently.  If your piano drops notes when you don't pump
hard, get it fixed.  Once you can pump gently, you can play with
expression.

Third is a to develop a theme technique.  I think that I do this by
pumping theme with one foot and filling in an overall level with the
other, but I'm not quite sure.  If that's what I'm doing, I also toss
theme from one foot to the other to prevent tiring my muscles.  Certain
aspects, like ffff or sFz, need the full expression to come from both
feet at once.

On my street piano, I adjusted the split soft rail for maximum effect,
hauling the hammers as close to the strings as I can while still
retaining their ability to speak.  Because the rail works from levers,
not buttons, I can easily cause lesser degrees of softness by moving the
levers only part way.

There are interesting things you can do with the tempo lever, but I
am not skilled at its use.

Some rolls have very badly done sustain (loud pedal) perforations.
I've marked those rolls "turn sustain pedal off", and if sustain is
needed, I toss it in by hand with the lever.

It's tempting to the novice pianolist to pump with the beat of the music.
This method is not quite correct, even for polkas and marches.  While a
lot of the accent does belong on the beat, sometimes it goes better
elsewhere.  This is especially true for ragtime.

Peter Neilson
Sanford NC