re: For those that track expenses on a spreadsheet, what categories do you have?

Interest expense - mortgage
Interest expense - CC / Auto / Other (if applicable)

I run an accounting firm and after a few years I found it easier for clients, and myself, to track this specifically because we have found errors on 1098s. Also helpful to show other cash outflow to clients for not paying down their CCs or other financed capex (or the spouse that is abusing a CC).

I’ve found a personal balance sheet to be very helpful as well. If you’re going to track income, might as well track your assets.