I know at the beginning of our careers, my wife and I were gut wrenchingly competitive.
One other thing, if it's possible, as songwriters, you should also develop yourself as record producers.
I've written songs sober and I've written songs high.
A guitar riff played on a piano doesn't come close to the purity of it being played on a guitar but I faked it enough to get by.
You're going to have more rejection than acceptance.
I get a different kind of lyric from someone else that might make me go in a different musical direction.