I use left over fencing material that I fenced in my garden with. I have tried making large round cages, but the spacing between wire is a little small for me to easily fit my hands through. People with smaller hands it’s a little easier, but overall I have found that unless it’s very easy to tie up vines, things become easily too crowded.
For me, it ended up WAY easier to just put another line of fence inside my garden, and grow flat on a fence. I feel tomatoes are also a little more productive, but it could just be that it’s easier for me to prune and pick off horn worms etc this way. Also very easy to harvest.