"Best Practice" is to check the lug nuts on all TT wheels with a torque wrench before every time you tow, and check air pressure as well.
The scrubbing action and the lateral forces against fixed TT wheels when parking and in tight turns
may cause the lugs to loosen. There are many variables here as mentioned in previous threads. I usually check mine a few times per season using a torque wrench that I carry in my TT's tool box. Most of the time they are fine, once in a blue moon I find 3 or 4 that have loosened for whatever reason, so I continue to check them.
There was a guy who posted on this forum way back in 2001 (when it first started) who took his brand new Sunnybrook out on the NJ turnpike and lost 3 out of the 4 wheels, wound up crashing and totaling his new Suburban and trailer. He was suing everybody he could find claiming that nobody told him he needed to check the lug nuts, including his insurance company who found him liable for the accident for failing to check the lug nuts....I believe his user name was Marty, I know some of the old timers here will remember who I am talking about.
Bottom line, get yourself a torque wrench and carry it with you. Check your lug nuts periodically.
By the way, Car Craft magazine tested the Harbor Freight torque wrench and found it to be just as accurate as the Snap-On and Craftsman, read about it
here.