I guess my workflow is sort of different but it's what I'm used to.
I work in parts, meaning I make a new pattern for every new part. I name my parts A-B-C and so on. Sometimes I use other structures though.
I have my instruments sort of wherever, since I don't like leaving the piano roll so often. You can use the "back" or "forward" mouse buttons to pop up the menu where all your instruments are, or you can click one of those buttons on a ghost note to start editing that part. I have done a few songs using only on pattern too. I have also made songs the "normal" way, building with short looping patterns with variations.
Mixer is fairly simple, I tend to just select all my instruments and ctrl+l to auto map them. Drum and bass is normally on the top for me.
Automation is something I'm experimenting with. I often use the playlist to edit automation. When I feel it's faster to just record the automation I do it that way.
When it comes to composing, I like to start with a chord progression then proceed with a melody and just fill in the rest. If I'm lucky I don't hit too many road blocks.