when I am binding a circle I too use bias binding, fold binding in half press and attach ,when I get to the end about 3" from the end I stop and join to the beginning which I have left un stitched about 3" from the beginning. This will give you a more finished seam so you don't know where you have started or finished , by the way after you have joined the two ends together you finish stitching on to the circle you can sitd or hand finish. good luck.