I came across this video on Youtube.
From the poster:
*While experimenting Boolean modifiers, I came across a new method to model low polygon models fast. *
*In order to do this, you need to do the following: *
*1. Create a cube, go to Edit Mode, press  to go to the Vertex mode. *
*2. Press [Alt + M] and combine at the center. *
*3. Use that single vertex to make outlines of each view meshes (Top, Side and Front) via extruding vertices. *
*4. After all outline meshes are complete, fill and extrude all 3 meshes. *
*5. Use the Boolean modifier to intersect all three meshes and we get the final result. *
*I have tried this method in designing complex modern airplanes and helicopters and they worked really well. *
*All we need to do, for low poly projects that is, is texture painting it to complete the work. *
For other work, we’d follow the same reptopoly steps for we do after sculpting is complete.