Mine are 4 x 8, and built out of 2 x 12's. Tall enough to not have to bend over is a good thing (mine aren't!), and as wide as you can reach in without having to step into the bed. Mine have access on all sides, so I only have to reach 2' in anywhere around them. Mine do have landscape in the bottom, but mostly because I tend to overdo anything I build around the house. We raise rabbits, so they are filled with composted rabbit manure, and when the leaves fall, I take out about half the soil, layer in the leaves and wet them thoroughly, then put the soil back in on top of them. The landscape cloth covers the entire area of both beds, and then some, and the beds are surrounded by patio paver stone. When weeds start up between the pavers, just spray some roundup and roll on from there.