Schedule reminders, document repairs/upgrades, manual storage!

Take the time to schedule auto-reminders in your calendar for things that regularly repeat, like checking your insulation, scheduling a chimney sweep, changing various filters, smoke detector checks, water heater maintenance, etc.

Start a spreadsheet or other document to keep track of every fix or improvement you do--new dishwasher, roof repair, window upgrades, etc.--with the date, product/contractor, and cost.

And we have a big expandable file folder thing where we keep manuals and warranties for appliances and equipment. (Go through it every couple of years to weed out instructions for things you don't have anymore.)