Just push them down over a small plant with the prongs in the ground.
Here is another great article about how to make them at Mother Earth News, Using Wire Mesh In The Garden.
Here is wooden type of tomato cage Woody’s Folding Tomato Cages.
This blog was created as a resource for families and individuals to find information about raising your own food and saving seeds. It includes information about how to save seeds, lists good sources for seeds, how to trade seeds, and the importance of seed saving.