I am not sure what kind of machine you have. I have a Viking and there is an edge-joining foot available that has a flange in the middle to guide with (they also use it for stitching in the ditch). My machine has the capability to move the needle in small increments to both the right and the left and I just move the needle to where I want it. If you have that feature on your machine, could you use a foot that allows you to move your needle over closer to the edge?