I simply hammer the rebar stakes into the ground next to the plant and tie the plant as it grows. If you drive the rebar pretty deep, it never fails. Here in Louisiana we have tropical storms and hurricanes and I've never had a tomatoe stake blow down.
My husband rigged up a thingee that pulls the stakes up at the end of the year ... mostly unbent. If a rebar stake does get bent, I put it in the vice on the workbench and unbend it.
