This applies to all lists where the contents are grouped by "box", e.g. when selecting a particular project or context from the left menu (and it also applies to the left menu itself):

Now the "boxes" (the GTD categories) are listed in the following order in all lists:

Next
Scheduled (clones only)
Someday
Waiting
Scheduled (mother tasks only)

I propose that Waiting For should come straight after Next, i.e. the following order:

Next
Waiting
Scheduled (once-off tasks and next instance clones only)
Someday
Scheduled (repeating mother tasks only)

Why do I want Waiting higher? Because a Waiting For action is somebody else's Next action and it might be finished anytime now, even today. Who knows, maybe I'll get the mail or package in just a few minutes! So I want to see these more easily and be prepared for receiving whatever it is I am waiting for.

Scheduled (including Tomorrow) could not happen today, so it should come only after Waiting. And Someday/Maybe are things that I am not sure I ever want to do, and I do not need to review them often. They can be even farther down. And the repeating "mother tasks" usually do not change at all and could remain at the very bottom.