I do backwards BTB with my hands pointed toward my back. While I was trying to learn forward BTB today (ouch) I was alternating between hands pointed forward and hands pointed back. There didn't seem to be much change in difficulty between the two (both equally *#$@ing hard), but I think it reverses the direction of hand movement you need.
eg "backwards BTB hands pointed toward back" you are doing the backwards weave hand movement,
but hands pointed away from back, you are doing a forwards weave hand movement.
errrr. i think.
my head hurts now.
from thinking and from repeatedly whacking it with bloody silly swingy ball things.
_________________________
"Switching between different kinds of chuu chuu sometimes gives this "urgh wtf?" effect because it's giving people the phi phenomenon."