I need to cut 1/4" strips of walnut and maple from boards that are roughly 4"-6" wide. My only means of cutting are with a circular saw. I am unable to keep the base flat on the board so my cuts have a slight angle to them or have blade marks along the cut. I have built a couple of jigs, but even after setting everything up, I still end up with a lopsided cut. A guide won't help due to the combined width of the board and the saw's base. Any suggestions would be helpful. Thanks.