Here are a few things NOT to do if you want to be good to your piano:
Use the piano as a shelf.
Plants and flower arrangements can result in permanent water damage, ruining your piano forever. Candles can drip wax into places where it cannot be removed, and cause heat damage to finishes. Picture frames can scratch the piano and rattle when the piano is played. Also, keep in mind that your piano technician needs every item removed from the top of your piano in order to tune and service it, so why not just treat the piano as an instrument instead of a place to put things?
Expose your piano to direct sunlight (and other elements).
The regular cycles of heating and cooling damages the piano and the ultraviolet rays ruin the finish. Placing the piano too close to a fireplace or heating/cooling duct can is also something to avoid. Anything that causes the piano to experience changes in temperature and humidity is something to avoid whenever possible.
Don’t tune your piano regularly.
Regular tunings keep a piano stable. If you a piano is neglected, the string tension will drop, causing the piano to lose stability. It will take time and money to get your piano back to where it should be. Also, regular tuning allows your technician to stay on top of the many issues that can develop to cause problems with the piano's touch and tone.
Keep the lid open.
Many grand piano owners like the look of an open lid, but this invites airborne dust and pollutants to settle on the strings, soundboard, and iron frame. Some of the areas under your piano's lid are extremely hard to clean, like around the tuning pins. Years of an open lid will result in permanent cosmetic damage. Keeping the lid closed or installing a string cover will protect your investment.
Eat and drink around the piano.
Having tuned many pianos, we see the results of allowing food or drink near a piano, and it's not pretty. Once spill can permanently lower the value of the instrument with irreversible cosmetic or functional damage.
Ignore the advice to install a humidity control system.
The Dampp-Chaser Piano Life Saver system exists to minimize the impact of seasonal humidity changes on your piano. Whether you live in humid Miami or arid Phoenix, the level of moisture in the air changes throughout the year. The changes in relative humidity are what cause damage to pianos over time. Also, a piano stays in tune much better when humidity is controlled. We cannot stress enough the importance of installing a Dampp-Chaser system if you want to maximize the life span of your piano and avoid warping, cracking, and failure of action parts, soundboards and pinblocks.
Allow furniture movers to move your piano.
Moving pianos requires special training, knowledge and equipment. We've seen and had to repair damage to literally hundreds of pianos, all caused by furniture movers who told their clients they knew how to move pianos, but clearly had no idea what they were doing. If you don't hire professional piano movers, you are asking for trouble.
Change the temperature frequently.
Pianos do not respond well to large or frequent changes in temperature. In most homes, the thermostat is maintained to a narrow range, which is a good thing. But in homes that are only lived in part of the year, and in churches, school rooms, and other spaces that are only climate controlled part of the time, pianos do not stay in tune very well. Saving money on heating and cooling only goes so far if your very expensive piano is destroyed because of it.