I have heard of 1 thing to do to make your music less pianocentric. That is to play other instruments. Thing is my commitment to guitar has always been on and off and while with an acoustic I don't really have to worry about sore fingers, with an electric guitar(which I most often play as I would an acoustic(so no amps, just strumming and plucking with my fingers)) I often don't know until the next day that I played for too long.
And it takes weeks for me to really develop the guitarist callous and be able to play guitar for longer. Also, I find writing for violin to be easier than writing for guitar. Maybe it is because like all my piano practice was classical music.
Yeah, I bet that is at least part of why I find writing for violin easier. I am planning on composing a country song for a trio of piano, guitar, and violin. And like I said the one thing I keep hearing is "Play more instruments. It will get easier as you get more advanced in more instruments."
But if it took me like 6-7 years to be super advanced at the piano and almost another 3 years to be comfortable playing super fast and not hit a tempo wall, I can't imagine how long it would take for me to get to advanced level guitar, especially with my on and off commitment to the guitar and almost constant commitment to the piano. 1 up side of having played the piano first is I can have a wide span between frets which is why I am able to play an open position Bb major chord with ease.
But I don't want to wait until I am better at guitar to compose music involving the guitar. So if I am only beginner level at guitar and thus can't really get into the guitarist mindset, how can I avoid writing music for the guitar that would really be more suited to the piano than anything else(such as close position 7th chords just as an example)?