hey

I find that when learning the butterfly, it was easiest to hlod one hand kinda resting on the other, so that one hand was slightly higher than the other and slightly in front.
The first butterfly I learned was the one with the Poi moving in at the top before crossing, and my left hand was upper.
Bear in mind that there are at least 4 variations to a standard front of body in time butterfly;
-left hand on top poi in at top
-right hand on top poi in at top
-left hand on top poi out at top
-right hand on top poi out at top
you can switch between which hands you have on top, either alternating quickly or switching once for a few counts etc etc. I think its very important to learn all four variations and be able to switch between them fluidly. This will allow you to go circular with your butterfly (something I aspire to doing, and I'm practicing towards). I can do a butterfly crossflow to the left at the mo, and I'm working on going circular...I hope to have it ready for the interstate poi off in Sydney in April.
So yeah. once you get the first butterfly, start working on the others. 
I hope this helps, if you are still having problems, post again. also - the more detail you post about what you are doing the better...
good luck,
Josh