Trailer sway is something that anyone hauling a trailer has to deal with or that anyone hauling a camper must consider. Sway is a huge issue with those that have travel trailers as it can cause damage, low gas mileage, and can make your trip far less pleasant. You first need to keep track of the tongue weight and the weight distribution of your trailer. You want to avoid putting too much weight on the back half of the trailer, past the axels.
You also want to ensure that your tires are properly inflated. You need to check your weight distribution hitch adjustments and you also need to take into account the actual sway controls that you have in place.
It can be so difficult controlling trailer sway if you do not take the time to adjust the trailer properly.
When you are actively driving, things like crosswinds, other vehicles on the road, the grade or steepness of the road, and more can all have to do with the swaying of the trailer as you drive. It is also important to have the right vehicle to pull your trailer. By taking your time, you can certainly get rid of many of the issues that may be causing your trailer to sway and can figure out what needs to be done in controlling trailer sway.