small block plane to take the sides down and the same for the top and bottom. But care must be taken to plane from one side to the center and not the full length of the wood. Running the plane the full length of the wood can cause splits in the wood. So always plane to the center of the side you are planing...turn the cajon around and then plane up to the center again. This will prevent splits etc. Once the sides, top and bottom are planed the cajon will start to look like the finished article. Next I use a rasp to put a little rounding on all edges and corners. Then finally I use an orbital sander to smooth out any tool marks and and get the wood to feel good. At this point you can put a logo or design on the front of the cajon. Then it is time to oil or varnish. I prefer oil and I use a teak oil on the cajon. But it could be given a few coats of varnish with a light sanding between coats. When that is done and the finish is dry, the last thing to do is fit some feet. I am using rubber feet and I simply fix them on with screws. And that's it. You should now have a completed cajon which is going to be very light to play because of the thin playing surface. It will have a good crisp snare sound