I just reset the trip counter before I leave and snap a picture of it as soon as I return. Then put the mileage into a simple spreadsheet, no extra cost.
I just do actual expenses. (Truck payments, insurance,
gas, oil, etc) It’s one or the other, and I have always found them to be very comparable.
But I suppose that’s only an option if it is a designated work vehicle…
I use ISN for my services and when you complete the info for the location it gives you a google map with distance to and from job site. I just keep the printout and add up the miles to and from job at end of year, and have a paper document showing where I went. Any stop or diversion from that piece of paper doesn’t matter only counting to and from.