Whatever works for you — but somewhere you know is the source of truth.
Whatever works for you… but somewhere you can put everything you need to do, and somewhere you know is the source of truth.
I use the Apple calendar. As a family we all have access, and it allows me to combine two places of work, family commitments, and personal to-dos in one place.
For work, I personally time-box actions — otherwise they don't get done, especially the boring ones. As someone who's very pressure-prompted, this is the only way I've found to not put these things off.
It must be always available to work — well, in my experience. If I don't add something pretty immediately, it won't happen.
There are loads of choices out there. Find the one that works for you — it's a bit of trial and error from an actual tool viewpoint.