Try to position the sensor so it is as untilted as possible - it should be level with the ground front to back and side to side. You will need to recalibrate the sensor for the best accuracy, as it is likely to be slightly tilted in one direction or another.
If you switch this same sensor between shoes, you should recalibrate it for each shoe after each switch. If that is your plan, it would be wise to measure off a quarter mile calibration area near where you usually walk or run and use that route for recalibration as needed.
