i still have a calendar on the wall and use a pen for important stuff coming up (and crossing off days just feels productive) and i use my ipod as a reminder (otherwise DD is a vocal reminder of things that concern her - very vocal and will physically poke me if i don't listen (and she doesnt really have a snooze button)
I tried to use Google Calendar to organize things, but I found that the act of actually writing things in a planner and seeing them all fit together really helped me, so I switched to that. I do set alarms in Google Calendar for REALLY important stuff that I can't miss (such as hosting chats like Courtney mentioned). Those alarms sync to my phone, which means that my Apple Watch will also go off. It's hard to miss something when every device lights up to alert you at the same time!