What chassis are you on?? What year.??
1st, If you're on a Ford F53, Regardless of the age, I'd do the
Cheap Handling Fix (CHF). It won't do a lot to improve the ride (bumps on both front tires at same time, i.e. seams in road ) but will significantly improve handling. i.e. hitting a bump on one side of the road cause the MH to wander all over the road, cross winds, trucks passing, etc.
2nd - If you have an older F53 (or any chassis), If you're more than about 7-10 years old, consider changing the shocks as they are probably worn out. This will significantly improve ride and handling. I installed
standard Monroe's ($50 each) and WOW, what a difference.
3rd - Consider air bags on all four corners, these will help improve the ride. I run my air bags at about 60 psi, this helps a lot.
4th - Look at your tire pressures, running the lowest pressure for your weight will help a little with ride, but will negatively impact handling. I've experimented with different tire pressures, I don't think I see a lot of improvement in ride or handling, I ran between 70 psi (minimum for my weight) and 100 psi. I just didn't see to much improvement....
These will improve the ride and handling, but keep in mind, you'll never get to the quality of an air ride suspension you'll find on more expensive chassis.