Look at the sidewalls of your Class C RV trailer. Look for the PSI rating. This reads as a number followed by PSI. For example, many Class C RV trailers have tires rated to 65PSI. Look for this on the sidewall.
Unscrew the valve on the tires and check the tire pressure with the tire pressure gauge. If the tires are low, inflate to the recommended PSI. Not only does this provide a responsive feel when driving, it improves gas mileage. If the pressure is too high, bleed out air from the tires. Over-inflated tires make the trailer feel top heavy and sketchy on the drive.
Pack all camping gear and equipment into the lower closet shelves and storage areas. Keep heavy equipment centered in the camping cabin and as low as possible. Keep weight toward the middle of the rig and as low as possible to prevent a top heavy feeling when driving.
Reduce speed going into turns. Read your owner's guide, or look at the sun-visor over the driver's seat for recommended speeds in turns. To further reduce top heaviness, reduce the speed by an extra 5MPH when entering any sharp curve or turn.
Mount any satellite antenna or communications gear to the sides of the trailer versus the top. Reduce as much weight as possible from the roof or top of the rig.