Set your first two frame posts in the ground about 1 or 2 feet deep and spaced about 3 feet apart. There should be 5 or 6 feet of post left aboveground. No concrete is required; just fill up the hole with dirt and tamp it down with your foot or a shovel.
Cross the tops of the two posts and secure them with twine.
Measure 6 feet along your planting bed and set the next two posts. Set them at the same depth as the first two, then cross and secure them with twine. You can stop here or repeat the process along your planting bed; it just depends on how much space you have.
Lay another post along the top of your frame, placing it between the crossed tops of the four posts you set earlier. It is a good idea to secure the top post with twine to prevent it from moving during stormy weather.
Drape nylon mesh over the top post of your frame. The mesh should reach all the way to the ground on at least one side of the frame. Many garden centers have mesh for trellises with grids ranging from 5 by 5 to 7 by 7 inches. These are adequate sizes for both beans and cucumbers.
Secure the mesh to your frame. You can tie it on with twine or use a staple gun to ensure it is tight and secured to both side posts as well as the top post.
Secure the mesh to the ground. Metal U-shaped stakes work best for this. Trim the mesh if you need to; it should be tight.