When it comes to producing realistic piano music inside FL Studio, from my personal experience as a music producer for over a decade, it's very important to start with a correct piano virtual instrument.

If any music producer, beat maker or sound designer is looking to improve their piano sound, the best way to do this is to download one of these free realistic piano virtual instrumental plugins shown below:

• Native Instruments "Kontakt 8" which comes with Piano UNO
• Decent Sampler Plugin - Basic Piano

These are currently the 2 best realistic and free to download piano virtual instruments.

After this, I would highly recommend music producers and beat makers to look up piano chord progression. This online chord progressional generator could help many music producers when it comes to ideas for realistic chords and melodies.

This is the best advice I could give to any music producer, sound designer or beat maker looking to make some realistic piano music within FL Studio.

FL Studio does come with "FL KEYS" but even with reverb post effects and EQ within the mixing and mastering, this piano sound output will not sound better and realistic as 2 free piano virtual instruments I have listed above.

Hope this will help you guys. If you have any questions, drop them below inside this topic and I will do my best to help out.