I keep three projects lists, but only 1 NA system. My projects lists are Projects-Home, Projects-Academic (which is my work) and Projects-Creative Writing (for my novels).
The NAs for any one of them could need to be done in any given context, so I put the NAs in their appropriate contexts and go from there.
And shh! I keep all the NAs for Projects-Creative Writing right in the projects list. Because they're really more subprojects/targets for the next thing to do during my daily writing time, like "Outline Novel 2" or "Write midpoint scene of Novel 1."
Collect. Process. Organize. Review. Do. That really is all there is to it.