Make sure you're feathered (zero thrust set), 1/2 ball deflection, 5 degrees into the good engine, and trim. Go full forward on the good prop you so always have full power available, lead all of your power corrections. If you need to take power off, only take off a little bit and put it right back up. See what that gives you. If you think you need to add power, then add a lot, and bring it back to about half of where you were before. i.e. if you're at 20" MP and need to add power, go to 24-25" until you see a response, then reset at 21-22". If you're at 20" and going high, reduce to 15" for just a second then go right back to 19-20" and see what that gives you.

Remember single engine you're 70-80% degraded... so you need to be 30 seconds ahead on what you think your power requirement is going to be. Come up on the power before dropping the gear, leave the flaps up if needed on the approach, and you can ALMOST never be over powered when single engine. Speed is your friend, it's much harder to get back once you let it go.