Some folks mount their cameras directly to their monopods, but this means moving forward or back,
should you need to point up or down. This fore/aft movement changes focus and perspective--and often contorts
photographers into odd (even comical) positions as they try to lean forward or back over/behind their pod.

Other folks mount a ball head on their monopods...but this introduces tremendous instability
via the unnecessary lateral movements available to most ball heads.

The solution?

-The only movement needed on a monopod is in the vertical axis.
This is the Manfrotto 3232, combined with the Really Right Stuff plate mount.
Together, they provide stable vertical axis movements, assure a secure mount,
and avoid the slow, uncertain properties associated with screwing your gear
to the pod each time.
-For panning movements, the monopod itself rotates freely, of course.

I highly recommend this set-up for anyone contemplating sound monopod use.