I do it the same way every time, but that is just me. I think the only convention is making sure that each channel is clearly labeled.
That said, I do things this way...
1 - Kick
2 - Snare
3 - HH
4 - Tom 1
5 - Tom 2
6 - Tom 3
7 - OH L
8 - OH R
9 - Bass
10 - Keys 1
11 - Keys 2
12 - Rhythm Guitar
13 - Lead Guitar
14 - Lead Vox
15 - Backing Vox 1
16 - Backing Vox 2
If there are other instruments they get grouped with similar things (ie. Percussion with drums, extra rhythm guitars with guitars...)
I think that most of it has to do with the way that you learned. I know that my system is a derivative of the system my teachers used...
That said, I do things this way...
1 - Kick
2 - Snare
3 - HH
4 - Tom 1
5 - Tom 2
6 - Tom 3
7 - OH L
8 - OH R
9 - Bass
10 - Keys 1
11 - Keys 2
12 - Rhythm Guitar
13 - Lead Guitar
14 - Lead Vox
15 - Backing Vox 1
16 - Backing Vox 2
If there are other instruments they get grouped with similar things (ie. Percussion with drums, extra rhythm guitars with guitars...)
I think that most of it has to do with the way that you learned. I know that my system is a derivative of the system my teachers used...