What is a quick way to make a support for pole beans for a 4x4 area?

Use an old wooden ladder. Open it up and set it in the middle of the bean patch. Drape the plants all over the ladder.

Purchase a piece of lattice at the home improvement store along with a couple pieces of wood to atach the lattice to - think of a headboard - and stake into ground. Guide the tendrils onto the lattice and let the beans grow!

I just saw metal trellises at the local store (Freds and Dollar General store) that sold for $24 each. A lot cheaper than the wooden trellises I bought before checking into other options. In my opinion, the metal ones would look nicer than most other options.

if you can brace a piece of plastic or wooden lattice from your local hardware store, that is the easiest for it to climb, or plant tall plants such as corn for them to climb (as the Indians did)

I used chicken wire stretched between fence posts.