I personally stopped using a planner for school and whatnot, and instead of something blocked with a cover on it that I can easily ignore, I have everything typed on calenders I found online and then printed, and placed into clear page protectors. I will either tape that calendar to the notebook for the class it applies to so I’m forced to see it, or keep it on my desk or taped on the wall next to me. I also have a dry erase calendar on my fridge as a second source of barraging me with info. I used to dabble with different phone reminder apps and other apps for ADHD people but found that I used them for a week tops before I just forget they exist. On my tablet I rearranged my home screen to remove most icons and instead have a giant calendar and memo pad as the first thing I see, which usually I usually write overly sassy notes to myself to remember to do things.
My advice is always when in doubt, leave yourself sassy notes. No one wants to wake up and see a long to do list of stuff, but finding funny or sarcastic post-it notes around the house or memos on your computer/phone can be more engaging. Mine usually says things like “You know damn well that your paper is due tonight at midnight” or “Hey remember the last time you forgot you had a test and studied until 6am? Lets not do that again. *list of test dates for the entire semester* ” I usually put them near my computer, on the fridge, bathroom mirror, etc.
I’ve really just noticed that some people with ADHD do better with physical pen and paper reminders. Tech can be a slipperly slope when you look at your phone, and then end up mindlessly scrolling through facebook or watching cat videos for hours, forgetting you ever saw the reminder.