I have used 7 foot bamboo poles from Home Depot in a tepee shape and I have used various recycled items like a soccer net frame with poles leaning against it and string wrapped around it for better vine support.I have rescued several "found" items from the curb on garbage day as well. Old baby gates, and frames from broken structures make good supports.
Beans can grown more than seven feet so you either have to prune them or let them flop over on the other side.

I use four metal T posts and 16 ft cattle panel to make an arch and plant one seed by each crossmember (on each side. Im 6 '3" and have jsut enough space not to be cramped most of the beans hang down in ur face for easy picking and some hang on the sides. Last year I expanded this to 20 panels and found it to be the easiest bean trellis ever. I might add that i also use river cane (small bamboo) that grows here in southeast Tennessee on rivers and creeks to make teepees. Gizzard

I do something much like Gizzardmaters, except, instead of making an arch I hang that cattle panel, about a foot off the ground, on two T posts. This makes a "trellis wall." Works real nice and I think it's a bit more space conservative.

George
Tahlequah, OK

I have made the cattle panel trellises but lean 8' plastic coated poles toward each other to make an upside-down V. But lately I've been buying trellis netting from online nurseries in like 50' lengths and stringing it on plastic-coated wire between heavy T-posts so I have more area. This year I bought some plastic trellis from Johnny's that is very cheap- $58 for 250', 6.5' tall, but the holes in the trellis are 6.5" and now that I have it I think that is a little large as it makes kind of big spaces between plants. I will probably end up with more that one vine per strand. I also don't know how many years I will get out of it. The trellis netting is made of nylon and has held up several years so far.