Some PVC tubing makes inexpensive and handy tarp support bows.
This trailer mod comes courtesy of the Bantam Trailer List, with a great blueprint posted in the Files section (membership required).
The supports are 1/2” schedule 40 PVC pipe with some 90 and 45 degree elbows. I didn’t even glue things together - keeping the unglued lets me shift a bow assembly back and forth by pushing one side at a time.
Here’s the main benefit - using a tarp over the trailer. This is just a temporary 6x8 plastic tarp. I plan to have a black vinyl one custom made soon.
This setup worked great at the campground - the tarp kept all the junk from the trees from getting into the trailer and also provided some reasonably secure storage for the cooler, etc.