We have three 14’x4’ beds (14’ because that’s how much space we had.) They’re in parallel rows with about 18” between. Each has a cross-support midway with a 1x12 plank on top, making a walkway - mainly used by the cat, but we use them as a shortcut to get to the other side without walking all the way around the full length.
^^^Easy access to the full beds with four foot width! I guess if you play for the NBA, you could make it 5’, but your back and arms will thank you for only having to lift heavy plants and produce across 2’. The only thing I’d change maybe is making the crossing planks 2-by’s for more stability, but we were using up scraps.
We have a 16’x4’ bed against the side yard fence, and I would definitely have made it 3’ deep max, b/c it’s a PITA to get to the back of the bed, climbing over the plants in front. We now have some 12” square pavers as landing places when we wade in. This bed is at right angles to the three parallel beds with a 30” path, which allows room for the wheelbarrow, soaker hoses, etc.
I would probably like three beds in a squared-off C, corners not touching, so that I could sit in the center with a cold drank and survey it all, but when your entire lot, house and all, is 0.15 acre, ya do what ya gotta do!