I tend to work on my tracks from the very beginning, with the end in mind.
You must have some sort of idea what you want the finished song to sound like or you will be spinning your wheels for a long time. I'm not saying things can't change or evolve as you work, because they can and do, but you need a goal of some sort.
In other words.... as you are working on recording the tracks and getting the project together, as soon as you can reasonably do so, start using the volume envelopes, EQ and other fx in the tracks. You want to work towards having the project sound like you want it to sound when it's finished.
I tend to start with bass, drums, and rhythm of some sort..... then I build from there in the recording process.
As you work, it should be sounding more and more like the song in your mind sounds. At the end...when you rewind it to the beginning and press play and listen, it should be complete and exactly like you want it to be. At that point, all you should need to do is export it as a finished wave completely mixed. I use the WHAT YOU HEAR preset for export. Not all the Sonar DAW's have that preset as I understand it.... so if yours doesn't, find one that does export the tracks to a stereo wave that sounds exactly like the playback. Yeah, whether it's called mix, export or bounce.... the main thing is that it sounds like the playback.