I've not tried staff yet, (looking for one at the moment) but i know how much poi hurt, i remember limping slightly after finally learning a behind the back weave because i'd bashed my ankles soo much.
My advice would be to work with them one at a time, take it slow, and if you find yourself going out of plane, purposefully move your hand position to make it go out, then move your hands to bring it back in, it'll help you with associating hand positions.
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I have never killed a man, but I have read many obituaries with great pleasure.
- Clarence Darrow