Musicianship improves with....?

As a Kodaly music educator, musicianship is a very important aspect of my life.  I started college as a music ed major with voice as my "instrument", but switched to piano after two years.  Initially I was focused on secondary choral education, but that interest quickly changed to elementary general.  So, I sing and play.  I still spend a lot of time teaching choral music, but to elementary students.  And I began teaching recorders as a part of my curriculum to fourth and fifth grade students.
I've found that as I teach vocal production/choral techniques, and instrument techniques, my own personal understanding, approach, and experiences play a big part in how I teach.  The more (understanding/approaches/experiences) I have, the better I am at teaching the students.  It's amazing to look at my progress as a musician and see how my teaching has changed with my progression through musicianship.  They really are connected.  Every time I figure a different way to approach something as a musician, I think "wow, I need to teach this to my students!"
A year ago, I decided to take up the guitar.  First, let me tell you there are a lot of differences between piano and guitar playing.  One thing, guitarists don't often read music from the staff.  Then you have different hand positions and finger numbering.  But, the experience has improved my musicianship.  Being able to pick up a new instrument gives me more experiences to draw on in teaching my students.  And, of course, my students think I'm really cool because I play the guitar.
I began playing the piano for church services and their choir.  The choral director made the comment last week that it was really nice to have a pianist who also sings, because my understanding of voices comes out in the way I play and helps the choir so much more.  Strangely enough, I had never thought how my choral background affected the way I play.
I've also found that when I'm playing or reading music, I'm now starting to analyze the chords and progressions.  Music theory was not a favorite subject in college, even though I was good at it.  (Math!!)  But, strangely enough, I'm now embracing it as something that explains the "whys" of music, helps with memory, and improves me and my performance on the whole as a musician.
So, musicianship improves with... experience, age, practice, time....  And performance improves with musicianship.