craftgrrl | Sewing / costuming question

Even though Halloween is still 7 months off, my friends and I are doing themed costumes this year, and I'm the only one of us who sews. So guess who gets most of the work to do... :)

I imagine I'll have lots of questions as time goes on, but here's the first...

I need to make a petticoat type piece to go under a skirt and make it really poufy... I have plenty of tulle, but the question is how to get the most poufiness out of it. Should I make a very simple skirt and sew rows of tulle to it, or is there a better way of doing this?

Thanks in advance for the help! :)

(As an aside, for the curious, we're doing Alice in Wonderland, but we're going more for the America McGee's Alice (video game) look than the Disney look... I get to be Alice... :) )