The 180 weave is a beautiful little move that is a joy to perform. You should learn it from left to right and back again. Once you have it both ways its a heck of a lot easier to progress to the 360 weave which is just a sublime thing indeed. Start by doing a forwards 3 beat weave, when the poi are in between their 2nd and 3rd beats, instead of putting them over to the other side of your body, turn your body 180 degrees. If you time this correctly and continue doing exactly what you were doing with your hands to achieve the 3 beat you should be OK. Be prepared to go into the reverse weave when you have done it though. Try to notice the fact that its not the poi that have changed direction, its you!! :)