I've used zip ties a fair bit, but I'm not really happy with their springback ability. After several wearings, if you do any bending at the waist, the ties tend to develop a permanent crick, which can make the below the waist bit of the corset try to poke outwards.

It's an ok solution for one time wear or a learning piece, but not so much for a real sturdy corset.

I've had luck with using hemp cording - if you use the Elizabethan style of cording the entire piece, really seems to stand up much better if you need stabalizer in a pinch. You can even just cord layers of underbody and then top the whole thing with tacked on fashion fabric if you don't want the look of a gazillion little stitching lines. You can also get that at the hardware store.

Very well timed post, considering the use of green clothing and accessories in Iran to express discontent with the recent election. I was especially interested in the Iranian soccer players, 4 of whom have been expelled from the team due to wearing green wristbands.