This is my current system. I'll update this page as I revise the system to better meet my needs. This is available to you so that you can take from it whatever seems useful to you.
My system currently consists of a deck of index cards I bring with me everywhere, a digital calendar, and three notebooks.
In my wallet (passport size), I keep a deck of index cards bound together with one of those small metal binder clips. I might eventuall go into more detail about the methods I use to manage this deck, but the short version is that I put the card representing the current day at the front, the most recently used cards behind it, and the new/recycled cards at the back. I only use one side of each card at a time, and when I'm done, I draw an X and flip the card over, moving it to the back to be reused.
I primarily use this deck as a place to do the following:
Digital calendars are regretably not made of paper, but they are incredibly handy, especially if you're married and need to maintain a calendar synced between two people. I tried using a paper calendar, and it just didn't work as well. This is one of those situations where it's very handy to not be religiously tied to an inconvenient ideal.
I often find myself thinking about something obsessively. This often gets in my way of being productive. The solution I found is to have a single notebook that I write all my thoughts in. I find that this brings a sense of closure to my mind so that I can let the thoughts go and focus on other things. It also gives me a record of my thoughts that I can refer back to.
Sometimes my mind feels cluttered, and I want to write stuff down without having to worry about how it's written or whether other's will eventually read it. I solve this problem by having a dedicated journal for things like this. When the journal fills up, I'll burn it. I think this is more convenient that simply using individual sheets of paper, but maybe you would prefer those. This part of my system is essentially like "morning pages" if you've ever heard of those.
Since I'm planning on burning the notebook, and since I never review the notebook, I have to make sure that after I write something in it, I review what I just wrote to see if there's anything that needs to be written somewhere else such as in my card deck.
My purpose for journalling is to gain a more zoomed-out perspective on my life. To obtain this perspective, I find it helpful to review my journal every now-and-then just to check in, and to write about the following things: