Due to the wide frequencies a piano occupies, a number of processes will normally need to be followed in order to get a piano mix to sit naturally in a track. See below for a list of important procedures that are recommended.
Panning is basically using the stereo for effects. The are a number of different ways you can pan a piano. To the left or right around 50%, to the middle or full for a wider sound. They all have different effects and the best one to choose would depend on the instruments already on the track.
The below screen shows a typical 4 band compressor. Note how the left and right bands are push the to out extreme frequencies with 400Hz in center, the split point. The left and right side should differ slightly for the best effect. Be sure to set the lowest and highest bands attack value to slow for the best phrasing.
Set the release time to Auto and the Gain Reduction to around 1dB. Over compression may have undesired results.
The low end of a piano can tend to interfere with other instruments such as a bass therefore set a high pass filter cut of around 150Hz to deal with that issue. It is best to actually tweak this while listening to piano with a bass instrument at the same time.
At around 12KHz you tend to get a reverb sound. If it is starting to sound to fluffy then try cutting frequencies at around 500Hz, and if it still sounds bad then try boosting frequencies around 3-5kHz.
If the sound ends up too thin then you may want to do the opposite and slightly boost the 500Hz frequencies and at the same time insert some saturation.
Now the result may sound very spacey or airey however this is perfect for when mixing with other instruments.
If you do need the piano sounding a little more dominating then then next things to add would be a slight delay and reverb. Do not confuse the two though, a delay is more like an echo and is often used in electronic type music also. The reverb simply extends the sound.
Sense of distance
Sometimes you may want the piano to sound like it is in the distance.
A good way to achieve this would be to slightly cut around 1kHz in frequency and also add a limiter with a gain reduction of around 1 – 2 dB for the best results.
In any case experiment. There is no perfect way to mix a piano since everybody’s tracks are different. Styles of music and vocals are different. The above is a good guide however experimenting with trail and error is also a big part of the learning.