Instead of writing what you know, Austin Kleon advocates writing what you like. As someone who has always started with creating from my expertise, it's a revelation. It's simple, but profound advice for anyone who wants to be creative.
Draw the art you want to see,
start the business you want to run,
play the music you want to hear,
write the book you want to read,
build the products you want to use—
do the work you want to see done.
- Austin Kleon