If when sewing the binding on what ever size if you are not filling it with the back batting and top when folded over ,do this; using the walking foot sew slightly more than 1/4 inch. I find if it doesn't fold over and reach sewing line cheat and slither a piece off .
Putting the binding all round in one go makes aneat edge and corner with the special fold is so easy and not bulky. Always start part way down one side.
Small projects could be done without binding using the forget name. Then quilt. Right sides top and bottom facing and batting on top. Machine all round leaving an opening to turn through. Then quilt.