Cutting and Sewing Bias Binding
Begin with a fabric square or rectangle. Use a large acrylic ruler to square up the edge of the fabric and find the 45-degree angle.
Cut enough strips to total the length needed, handling the edges carefully to avoid stretching or distorting the strips.
Position and pin the strips perpendicular to one another with the raw edges aligned and right sides together. Mark, then join the strips with diagonal seams to make one continuous binding strip. Trim the excess fabric, leaving 1/4 " seam allowances. Press the seams open and trim the dog-ears.Download this Project 
Continuous Bias Binding
Rather than cutting individual bias strips, you can cut and seam a square to make a continuous bias strip. Start with a square or rectangle of fabric.
Cut the square in half diagonally to form two triangles.
With right sides together, align two short triangle edges and sew the triangles together with a ¼" seam allowance. Press the seam open.
Use a quilt marker and a ruler to draw parallel lines across the length of the seamed fabric piece. The space between the lines is the desired width of the binding strip, including seam allowance. For example, space the lines 2" apart for a 2" -wide binding strip.
With right sides together, bring the straight-grain edges together to create a tube. Offset the edges by shifting one down so that the top of one edge aligns with the first marked line of the opposite edge. Holding the fabric in this position, sew the bias edges together with a ¼" seam allowance. Press the seam open.
Begin cutting on the top marked line and cut in a continuous spiral. Each time you cut across the seam, you’ll be moving down one marked line.
Click here  to download a quick reference chart of the amount of continuous binding you can cut from various size squares.