Back in 2023 we published a blog about the do's and don'ts of using trekking poles: https://www.basecampoutdoorgear.com/post/how-to-use-trekking-poles
We found the below 8-minute video to be very informative. Skip to 3:50 for fit, 4:30 for how to use the strap, and 5:40 for using the poles.
Did you use trekking poles on your hiking trip to the Southwest? Do you have anything to add? Tell us in the comments!