I use a paper notebook. Each page is a day, each line a concrete task.

Each morning, I copy the unfinished tasks to the new page. It means that I must acknowledge and reprioritise each of them. Every task is either done, discarded or copied over.

The page is a physical limitation to how much work I can take. It's a reminder of my own limits. I also need to re-read the list every few minutes to find an item.

With this simple system, things rarely got misplaced. Not even little things like updating tickets or answering specific emails.