I, too, use leaders & enders. The only different is, I use the triangles I have cut off of blocks. they range from all different sizes. Once I get a stack of them sewn, I will then use them again as leaders & enders to make different block patterns. That way, I waste very little for scraps or thread & end up with bonus blocks to use in another project. I also do this with different size square blocks to make 9P & 4P blocks. I use all size extra blocks for this.