The Baron is a great plane, I've only flown the 285hp model but here are a couple tricks I like:
When you put approach flaps in, put in ~1/2 a roll nose down trim, balances out pretty well.
We use full throttle on climb, pull the props back to 2500 RPM at 500' for noise.
Don't use brakes immediately upon touchdown, or if you must be very gentle on them. Aero braking works well for them (pax may not like it though).
Getting a greaser every time can be difficult (at least for me), and they're easy to wheelbarrow when not used to the plane due to the nose being lower than the mains - be careful with that.
Carry too much power, or come in fast and they float forever.
They don't slow down as quickly as you'd think in the air.
Great on one engine, at least here in the flats.
Super easy to start unless it's 10 mins after shutdown - close the mix and put the boost pumps on for a few seconds and it should be good to go after that.
Faster below 8000' than above.
Missed approaches happen fast, especially if you're light.
Be careful on overtemping the heater.