Since college I've been using Moleskin notebooks (though lately Baron Fig notebooks) to manage my tasks/time one week at a time, moving over tasks every week that I didn't get done the previous week and evaluating whether I still need to have it at the top of my mind for each unfinished task. I find that it works extremely well for keeping relevant tasks in my head and only taking on larger projects one week at a time.
The system I use is loosely based off of the Bullet Journal method (link below), highly recommend checking it out if you haven't heard of it.