The following modifications are fairly common, I made two of them (Starred)
1: New and better shocks (Depends on what you have now)
2: Sway bars (Control side to side rocking)
*3:Stearing Stablizers (Try to keep you going straight down the road
*4: Track bars (One or 2) The theory which is good, is that when a vehilcle has leaf spring suspension the body can move slightly side to side on the axle If the front moves right while the rear moves Left then the body "Wags" like a dog's tail. .Sitting as you are, inside the body you preceive this as a change in direction and compensate. Which adds to the wag.. The Track bar, also called a pan-hard bar. Locks the body over the axles (side to side) so this can not happen.
If your car has Strut suspension, then these bars are part of the design, Independent front suspension also includes this feature as part of the design, But motor homes have a one-piece front (and rear) axe which can benefit from the addition of a Track Bar.
How much difference did it make:
In 2006, Jan-2, I drove from Detroit to Las Vegas.. When I got there the towed was a pleasure to drive I mean I was very worn out by the Motor home.
I made the trip again in November of 2006, after the mods starred above.. The very same towed was very HARD to drive, squirrely as blazes after driving the big house.
Home is where I park it!