Just a few quick tips I haven't seen mentioned yet.
First, make sure your trailer is level when fully loaded and let down on the hitch. some people try to tow with the tongue too high or too low and that creates handling issues. I have a couple of trailers and I have separate drop hitches for each one (one's a 4" drop the other is a 6").
Level or slightly nose-down is preferred, the problem with nose-high is that causes the front of the trailer to want to "fall" to one side or the other and leads to sway and instability. Slightly nose-down is fine but can increase tongue weight and if you have Torflex axles instead of leaf springs you will end up putting more load on one axle because there is no equalizer like with leaf springs.
Second, make sure your trailer weight is balanced. If you throw all your heavy gear in the very back of the trailer it will reduce weight on the tongue, making it more prone to get squirrelly (and vice versa). Your rear suspension should settle a few inches when you let the tongue down on the hitch. If it sags heavily or barely settles at all, you probably don't have proper tongue weight due to balance issues.
I wouldn't say balanced, the weight needs change based on axle placement and other factors. Ideally, you want roughly 12% of the trailer weight on the tongue. 10% is the minimum guideline, 12% tends to work out pretty well. Hitting the CAT scales when packed and ready to camp is a good idea so you know how the weights are. Some trailers are tongue heavy due to their design and actually require more gear to be loaded in the rear in order to get the tongue weight correct. This is especially true of toy haulers, but it also applies to other trailers depending on axle placement, floorplan, holding tank placement, etc.
Last but not least, slow down when trailering in heavy winds! Your travel trailer is a giant sail and you never know when a head or tail wind will suddenly switch to a cross wind, especially when going through terrain changes.
Indeed, too many people speeding with their trailers thinking they're invincible and can cope with any situation that comes along. Slow down and enjoy the scenery! Not only is it safer but you'll get better fuel economy and save money. :D
2017 GMC Canyon Denali CCLB 4x4, 2.8L Duramax, Red Quartz Tintcoat, BMS Catch Can, GMC floor liners, Weathertech no-drill mud flaps, ARE Z-Series shell