Bullet journal advocate
As a freelance writer and magazine owner, I swear by my bullet journaling, though mine don’t look as pretty as the ones on Pinterest. For me, one of the benefits of the system is that you can amend it or look over it anywhere (without having to rely on wifi or devices), and somehow the to-do lists get more cemented in my brain by writing them down. I use the system mostly for work, and when working on features for several clients and running my own business on top of that, it helps me carve up time to be more productive. It makes me feel more secure knowing my life is (kind of) organised in a notebook in my bag, and not just somewhere in the cloud.