I am a firm believer in KISS (keep it simple stupid) and that allows me to not need reminders or spread sheets for any of my cars.
And it goes like this...baseline any new to me car.
Oil and filter every 5,000 miles, that means every time there is a "5" or a "0" third place from the left on the odometer the oil and filter get changed, hundreds do not matter, only a 5 or 0. Example, change the oil and filter at 180,xxx miles, next one at 185,xxx.
Spark plugs every 100k. I bought my truck with 156,change on it, I changed the spark plugs then, they will get changed again at 200k, then 300, etc.
Fuel filter, power steering fluid, driveline fluids all get changed every 50k. They were all changed shortly after I bought the truck, but they will all get changed again at 200k, then 250k, 300k...you get the idea.
Engine coolant drain and fill every 2yrs, I bought my truck summer of 2016, so next coolant drain and fill is summer of 2018, same with brake fluid, every 2 years.
Serpentine belts last forever, no need to change those unless it is squeaking, in which case you change the belt and tensioner at the same time, serp belts only squeak when the tensioner gets weak and they glaze over from slippage. Once glazed they're done, they will continue to slip and squeak.
Timing belt and timing belt driven accessories get changed every 100k, mine was done by the previous owner at 80k, I currently have 180,change, it will be changed at 200k, then 300k, etc.
grease u-joints at every oil change, inspect undercarriage for leaks every 10,000 miles, inspect ball joints, tie rods, wheel bearing play every 10,000 miles, so next inspection for those items will be at 190k oil change, I know this because I do that inspection at the "0" oil change.
If you label your oil changes "A" and "B" you will know what needs to be done when.
"A" schedule is oil and filter, grease u-joints, inspect ball joints tie rods wheel bearings, that is the "0" miles oil change (180,xxx)
"B" schedule is oil and filter, u-joints, inspect undercarriage for leaks, that is the "5" miles oil change (185,xxx)
Open the hood and check fluid levels every Saturday before the first start of the day, this takes all of 1min. No need to wipe the oil dipstick, just pull it out and check the oil level. Check coolant level in the over flow bottle, check power steering and brake fluid levels, top off washer solvent. Inspect battery terminals for corrosion.
Literally takes all of a min to do this, once you get into this habit you will notice if something is a miss and you will prevent breakdowns and other problems.
This translates to ANY car or truck that is in your fleet, your's, your wifes, your teenage daughter...
"My coolant level has been fine for the last 2yrs, why is it low during this weeks underhood check?" Instead of "oh s*** my trucks overheating and I'm late for work"
Or "I better do something about that battery corrosion this afternoon" instead of "my wifes in labor and my truck won't start"
You want to know the last time I needed a tow truck? 10yrs ago. The fuel pump went out on my wifes Volvo while I was across town at the dentist. The time before that? My 1995 Oldsmobile that I bought brand new was under warranty and the alternator went bad.
Pay attention to your damn car, it tells you when it needs attention, ignore it and it will leave you stranded.
Discipline equals freedom.
...
