When I make continuous binding, I usually cut my strips two and a half inches wide by the width of the fabric. It's a nice size. You don't have to play with it a lot.
So you take your first strip, lay it on your mat. Second strip, 90 degree angle, put it across. And the fabrics should be right sides together. Take a ruler with a 45 degree angle and line it up against the edge of the fist strip.
And what you're going to do is get a nice diagonal line there. And before you move it, you're going to put in a pin, two pins. And then bring it over to your sewing machine.
So at your sewing machine, you're going to want to sew on the line you've just drawn. When you take your pins out, you're going to have your continuous binding. The next thing you want to do is just trim off your seam allowance.
And that's how to make continuous binding strips.