Well, since you asked "How would you
do this", I'll get the ball rolling.
I would commit to one song at a time and see it through to completion. The reason I say this is that (for me anyway) it takes so much time and concentration to get something sounding decent. Spreading that concentration over 9 songs at the same time would frazzle my brain.
What's important is the end product should be evenly balanced volume wise - all nine songs. We once did an album with an "enthusiastic wannabe producer" buddy and it was basically unusable at the end. Some songs were brilliant and loud, others too soft and you would have to keep adjusting the volume on the playback device. We eventually paid for a more professional service.
My two new pence worth...