After starting our tomato plants from seed this year, we have many more small plants in the ground than in the past years. We are looking to make our own inexpensive and durable cages that we could use year after year.
What are starting materials that we can use? Are there materials to avoid? It seems that the openings in chicken wire and hardware cloth are too narrow.
Bamboo is one of the best materials. It is durable and lasts year in and out. If you have access to bamboo take advantage of the natural resources available. You can use as a pole and tie up the tomatoes or make it into a teepee style. Many garden shops will carry this material in bundles.
We use the same type of square grid sturdy rebar type fencing and lean two 5' to 6' pieces against each other down the length of the bed. We place plants about 18" apart on either side. Down the center, between the fencing, we cover the ground with black plastic, cardboard or other mulching materials to prevent weeds, and conserve moisture.
A concrete contractor friend of mine gives me the end-of-roll of this 6" square grid rebar (bit over 1/8" wire) stuff that he does not want to mess with. I have seen similar stuff sold as rebar and as fencing (thinner wire) in home improvement stores for $10-$15 a roll. One roll would do a dozen or more cages.
We're still using the supports we bought 25 years ago - generic metal fence/sign supports from Home Depot, or whatever was around back then. We just pound one in every 6-8 feet, and string nylon trellis netting between them.
This gives you a trellis about 6 feet high. It works best with indeterminate tomatoes. If memory serves, we got the idea from Square Foot Gardening (the old edition).
I perfer using a trellis as others have mentioned. See the pic in this question as an example. I bought nylon trellis netting off amazon for $10, 4 8' electrical conduit pipes, and 6 conduit straight connectors for less than $10 as well at Home Depot.