Last year, we used store-bought garden covers, which killed our plants. This year, we purchased sheets from a resale shop. They’ve worked reasonably well. (I completely understand that some plants simply won’t survive frosts.)
Most of our freezes have been right around 32 degrees. For colder freezes, we’ve thrown some towels on top of the sheets.
We use the cages, as well as rocks to keep the sheets from flying away in the wind.