As I've been practicing, I've noticed that one can never really bring the ship to a full and complete stop. There's always a small amount of momentum - be it horizontal, vertical, or rotational - and one can never ever hope to "bump" the controls enough to get the ship to hold still.
I'd like to see a keybind added that applies a small amount of deceleration to all movements, allowing the pilot to bring his/her ship to a 100% complete halt. This would only be usable if one is manning the helm, and it would only work for directions that aren't being adjusted by the typical controls. For instance, if the pilot has the throttle on and is turning but isn't adjusting their altitude, then this button would only stabilize the altitude. Or, if the pilot is adjusting their altitude but has the throttle off and isn't turning, then the key will halt any horizontal and rotational movement.
Obviously this can't be so overpowered as to be a go-to emergency brake. I think that the deceleration value should be no more than 50% of the normal acceleration value for any given movement - possibly only 25%. This way, if you're trying to stop from ramming into something, it would actually be more effective to drop to full reverse than it would to hold this key down. This is only meant as a means to stabilize a ship that is still moving a bit even after zeroing out the controls.