Notecards (I use the ones that are blank on one side, lined on the other)
Cheap and easy, and (bonus) you probably already have almost everything you need.
So here's what I did. I started by writing the date at the top, and then writing a brief description of what I did that day. Then, on the other side, I drew something to represent my day. Again, my art skills are sub-par. But that never mattered much to me.
Obviously it isn't perfect, but there are other options. If you'd rather use pictures, you can pre-write the notecard stuff, print the pictures that "fit" the event, and glue it on to the front. Or if you're too busy to do a card that day, you can write about your day in a planner and transfer it to a card when you have a little more time.
I like that if you feel like it, you can make an "about me" card, or answer a journal prompt, or make a list of things. It's super versital, fast, easy, and they're fun to go through. And, better yet, low to no commitment! What could be easier?
I hope I've maybe inspired someone who's more artistically talented than me, so that you can rock it ten times as hard, then show off my idea to people and be even MORE inspiring. Happy journaling!