Since I don't have a keyboard, I do everything in the piano roll
I usually start out with a chord progression, improv a melody, stick a drum beat over it, and start with that. Often times what I make better suits the first verse or chorus of the track I'm making, so I then proceed to make an intro, and verse, and so on until I find a place that my first pattern fits. I have each section in a single pattern (verse, chorus, etc), and clone them to add fills/transitions to the next section. Many of my song do not follow the usual Intro-verse-verse-chorus-verse-chorus-etc, and usually end up ending a totally different song then I started out with. I do not name my patterns or tracks.
For mixing, (drums take forever to mix sometimes, so I do that before even starting the song), I start by adding all of the effects to my drums, testing various drum loops and patterns to test the quality of my mix. Everything else, I tend to mix on the go. For any non-bass instrument, I cut out everything under 60-100Hz, and for some bass (if not acoustic bass), I cut everything or lower it a lot above 1kHz or so.