I used to use 4-inch record cards in plastic index boxes (from most office suppliers), which come with A-Z, monthly and blank organiser tabs.
I kept all my phone numbers in one - you can easily take some phone numbers out as a reminder to make calls, write additional notes on cards and rewrite a card to tidy it up, which is neater than a phone book. I kept all my appointments in another with 12 monthly tabs, with the current month at the front. If something got dealt with (e.g. dentist), then that card would go back in to the correct month for the next appointment. Birthdays and other fixed events would come to the front as all the preceding events were dealt with and went to the back.
I kept all my book and music records in another, again so I could handle a part of the collection (like taking all the cards for one author or group to the library, to be sure to borrow something new).
I got out of the habit when I was hospitalised for a while, and am just getting back to being organised again, but I found the individual cards much easier than note books.
