> There's something about manually writing and copying over TODOs to the next month that makes you really question if you still need to do it, and if you do, gives you a reminder that you still haven't done it.

This is also key for me. Striking through an item that's on my list for some time and that I just decided doesn't matter feels just as good as marking some item as done. Undecided items indeed go to the next list, and just the act of writing down the same item on a new list forces you to reconsider it.

List done? Timestamp it and throw it in the archive box.