[nst7]

Using sends like in the video is actually not the most efficient or simplest way to do this.

You can set up the audio tracks the same way, but instead of using a send to a buss, you simply change the output of your instrument track to that buss. So instead of the track's output going to your main monitor (1&2, or whatever), you would change it to output to whatever buss you want. The audio track would have the input set to that buss just like in the video. Only now you don't have to worry about pre-fader/post-fader, etc. Just record arm the audio track, and use the regular fader on the Instrument track to control the output to make sure you're not clipping. In most cases, unity gain should work fine, though if you have plugins on the instrument track (which will also be recorded), they might possibly boost the level a little, so you'll need to double check that.

Also, when you're done recording those instrument tracks to audio tracks, be sure to deactivate the instrument tracks so they're not using up unneeded CPU power. If you want to change or redo something later on, you can always re-activate them.