I have had an I phone for years now and have the latest one but still do not use the reminders as I dont really know how and dont look at my mobile all that much.
I therefore still use the old fashioned way of having a small diary on my desk that I write things into.
As well as this I also put things on a reminder on my PC Windows mail and it automatically pops up and tell me at a time I choose.
I also use a similar system for reminders for birthdays and other important dates.
Without these two systems, I would be lost and would not remember half of what I have on, and what I have to do each day!
I also have two calendars on my walls -one whippet dog one where my two babies feature on one month and a David Tennant, Dr Who one but I do not write on these as they are purely for decoration to gaze at!