|The finished bench was 60" long x 24"x deep x 34" high. Vary the dimensions as you wish!|
I began by cutting the 2x4's to length on my mitersaw. I cut 4 uprights @ 27" long, and 4 crossbars at 24". These were for the sub-assemblies that went at the end of the bench. I joined the parts with Dominos, but 1/2" dowels would be a good choice too. I cut the ends of the crossbars at a 10 degree angle because I like the look but you could skip this step.
Once the glue dried on the ends, I remove them from the clamps and cut 4 stretchers to 54" long. One pair went in at the top of the bench, and the other pair went in lower down, about 12" from the floor. I used 5" long Timber-Lok lag bolts to secure the stretchers. They have big, beefy threads that really make for a strong connection.
Bench heights are an enormously subjective thing- 33"-38" is generally considered the usual range. I'm 5'8 and like a bench that is around 34-35" if that helps at all. When in doubt, measure some of the work surfaces you already have and see what changes you might make.