I generally use stretch mesh or stretch chiffon (just be careful it doesn't ladder! There was a long thread back on TSF about a saga I had with some stretch chiffon, which laddered as I tried to pick it up to move it to the sewing machine. Now I test it for laddering before I choose it.)
If you do want to use actual chiffon, then polyester chiffon can have its hem melted by careful cutting with a hot-knife blade, or more careful melting with a lit candle taper. Don't try it with silk chiffon as it's not a "plastic" fibre, and will char rather than melt.