This really depends on the array of tools you have at your disposal. I had to make my girlfriend a Sailor Umbreon Staff (http://jfamily.deviantart.com/gallery/32342647#/d48imy0
) which was pretty simple.
I used a large doweling rod purchased at home depot as the base (pick a thickness right for you, I *think* I used a 3/4" diameter)
For the balls at the top and bottom I would most likely attack it with Apoxie Sculpt (Made by Aves Studios, 2sec of Googling will get you their site) and for the actual staff head I'd use wood or plastic (sintra) cut to the general circle shape then add apoxie sculpt to it for a rounder appearance.
If you are lacking in tools, since saws, sanders and dremels are required for nice woodworking/plasticworking I have seen lower tech staves made with craft foam as the staff head instead.
Good luck to you! I hope that helps, I'm not too good with typing explanations.