The best practice is to ensure your drivers are using true odometer readings for each jurisdiction. This makes it fool proof then the auditers do come.
We see all kinds, from zip code, to blank sheets with Toronto to Savanah, GA with nothing in between. Now you can build a trip, but the auditors do not in one second like it and work harder to find out if you are actually trying to hide something.
Complete trip reports with all fuel, tolls, etc is the most effective way of ensuring that the information is correct.
Last client who thought they could artificially inflate their KPL walled away with a 35000.00 fine. This is for 10 truck fleet.