Remember that removing or adding a leaf isn't the only tune-up.
The longest secondary leaves have the greatest effect on ride quality, because they flex almost immediately. Swapping in a shorter leaf of the same thickness generally improves ride quality, reduces height slightly, but still keeps most of the bottoming protection.
You can also tune your bump stop rubbers.
If the chassis has been lowered a lot and you're worried about ground clearance, remove the existing stops and substitute thicker (not taller) stops with flat tops (not cones or wedges). These are more harsh when you strike them, but stop more quickly.
There are also many generic shapes available in polyurethane from Just Suspension, etc. but they're pretty stiff.
You can stiffen the existing stops by driving wire brads through them parallel to the ground; drill a pilot hole first, and use soap etc. to press them in.

The reverse is also true: if the stop is too violent, you can soften the initial action (not the total distance) by shaving some rubber off the diameter (not the height) at the top. Hold the razor blade in Vise-Grips and wear armor gloves, or lose a finger (if you cut the artery at the base of the thumb, you have less than 1 minute to get help before you pass out).
Drill 1/4" holes parallel to the ground through the thickest part to soften the entire travel.

Last edited by panic; 04/09/2010 2:25 PM.