I have been trying to streamline my planner, journal, and to-do lists for years. Because surely, if I could only get organized enough, life would roll so smoothly. I had seen friends "doing" bullet journals before, but didn't understand the theory until I read Ryder Carrol's Bullet Journal Method. An adaptive way to organize your planner -- and combine/organize all your lists and notes, the biggest change for me is writing in months and weeks as I go, which means my pages adapt to the week's schedule. For example, here is what my planner looked like before (notice all the white space.)
And here is what it looks like after. I am trying to sketch and write in daily reflections, which is also part of the theory -- that events and thoughts have the same priority as to-do notes.
Plus if I go on vacation, I can scrap the planner structure altogether and just have fun:
Other additions that are helpful are an index and future log at front and a series of 'icons' that send your to-do lists in different directions. You needn't be an artist to use the system (Ryder Carrol isn't), but the artists have certainly taken to the journals in droves. Just check out pinterest for ideas and tracking systems. And, since I'm always looking for the "perfect" pen, here are my current favorite supplies.