Turn off the phone.
If you have wifi turned on, there are systems that can track you, like mine. I expect the same can be done with Bluetooth, and it definitely can be done via GSM.
Just because the software says that something is turned off, is it really? It's already been proven that Google have looked at locations even though people thought it was switched off.
If you have an Android phone, go to maps and look for your timeline, there's a good chance you can select any day from the calendar and see a map of all the places you have been. I once used it to prove that I wasn't driving a speeding vehicle, because I was 40 miles away at the time.
If I don't want ANY record of my location, it gets turned off at a place I frequent. Then I'm free to go anywhere without any record of me being there. When I've finished whatever I've been doing, I go back to the same place and switch it back on. Reviewing the data would just show a time difference at the same place, much more believable, especially if it's a pub :-)