The circumference numbers on the template are used to calculate the length of each tier. Any number of tiers can be used. For a full skirt each of the tiers must be full enough, around the bottom edge of the tier, to form a full flat circle with the dancer in the center. If the tier is too skimpy at the bottom edge, it will not spin properly. Also it may not fit down over the petticoat. If it is too long, the skirt will be too heavy and will fold into the petticoat.
Placing a piece of pattern paper over the template and drawing the skirt on it will help you get a visual idea of the skirt.
'Personal Circumference' - For a skirt with an elastic waist band use the largest body measurement, either hip or waist plus 2 inches. For a skirt with a solid waist band or attached to a bodice use the waist measurement plus 2 inches. The additional 2 inches are for design ease. This number is your Personal Circumference. Trace the curve that is closest to the Personal Circumference.
Measure from the Personal Circumference line to the desired skirt length and trace that line.
Divide the skirt length by the number of tiers and draw in those lines. For example - a 21 inch length skirt can be made with three tiers by tracing the lines 7 inches and 14 inches from the Personal Circumference.
The circumference number on these lines is the minimum length of the tier to make a full circle skirt. The tiers can be made a little longer but be aware that increasing the length increases the weight of the skirt.
The width of each tier should be 1 inch more than the design length to add a ½ inch seam to the top and bottom.
The tiers do not have to be an equal width. For example - a 21 inch length skirt can be made in 3 tiers of 6, 7 and 8 inches or 5, 7 and 9 inches wide. It could have 4 tiers of 4, 5, 5½ and 6½ inches wide or 5, 5, 5 and 6 inches wide. This is entirely up to the designer.
Note: After sewing the tiers together, I zig zag fishing line to the seam allowance and then topstitch it to the smaller tier. This gives the skirt some body and makes it look newer longer. Usually, 25 or 30 pound test works well.
Hems - You can make the bottom tier wider and turn up a hem. Or you can use a rolled hem either on the serger or sewing machine. Using fishing line in the rolled hem will make the skirt stand out better and keep the edge crisper.