Hi, ero213.

I use paper lists. I have a lot of projects and a lot of orphan actions. Still, I have
a feeling of confidence that I have everything (or close enough to everything)
recorded in my system(s).

When I finish an action and erase it from my lists, then I think about whether
there are any next actions to do now that that's done. It's similar to the Pigpog
method, where you write the purpose or name of the project next to each action
to help do this.

I don't rely on Weekly Review to get actions onto my lists. I write them in when
I think of them.

Ah. If you're writing lists of actions in your project support material, then maybe
that's giving you the feeling that you've written that action somewhere, so you
wouldn't tend to also write it in your next-action lists.

A project can have more than one action in the next-action list. The only ones
to leave out are ones that can't be done yet because another action has to be
done first. These can then be added as soon as that action is done.
(Maybe put an asterisk next to the action to show that you need to
add some other actions when you complete it, if you wouldn't just remember?)

If it helps, in the project support material if you have
lists of actions there you could put symbols next to them to show that they've
already been recorded in your next-actions lists. I put a slash beside an action
in any of my systems if I mean that I don't need to worry about it there
because it's been copied to another system, such as a more appropriate
context list. This is similar to a checkmark for when it's completed and means
I can quickly glance at a list and ignore those items.

I think in GTD the weekly review is supposed to catch projects that "fall through
the cracks" where you forgot to write in a possible next action. You could find
a way to do this kind of review quickly and do it more often than once a week
if that's what you need. Sometimes I use a one-page-per-project method
and can quickly look over them to get an overview and a feel for where I am
and what the next steps are in each project.