Electronic or paper depends on your preference and maybe age. I grew up with paper, and the first dayplanner i had in the business world was a franklin planner. I still use it as it makes sense and is in a format I became accustomed to. I tried a phone app but I am a hands on visual person, and that was too cloud-like for me.
I also eventually bought a smaller, more manageable classic sized binder when the location in Franklin-Covey Denver location was closing. Having a nice leather, durable notebook takes it too a level of importance making it not easy to overlook or forget. I was stunned recently when a person about half my age, where I was paying a bill, remarked when I opened it up “Wow–now that’s organization. I just try to keep things on my phone, but you put me to shame.”
I do best by trying to list only 3 important things to do a day that have an A (most important rating). Anymore and I get overwhelmed a bit. Good luck