The method I used to make it can easily be adapted to make a skirt with more tiers -- 3 would be very cute for a short skirt, 6 or 7 work nicely for a long skirt. The instructions here are for the 2 tiered skirt, but I've added notes on how to create a 3 tiered (or longer) skirt. Let's get to work:
Start by measuring your hips at the fullest point. If you're apple shaped, measure your waist as well so that can adjust to get the proper fullness at the waist. Now add 3" to that number.
The top tier of this skirt is 12" wide X 44" long (for a 41" hip measurement). If you want your skirt a little shorter, or you're going to create more than 2 tiers, then make the first tier 10" instead of 12"
For the second tier of the skirt, multiply the length of the first tier by 1.5 -- for this skirt that gave me a length of 66" for the second tier. Because I didn't want my tiers cut cross grain, I cut two pieces and joined them together to create a 66" piece. The length of this second tier will be the same as the top tier -- in this case 12".
Note: if you're making a skirt with more tiers, just keep multiplying the length of the previous tier by 1.5, and stagger the widths of the tiers. So for a long skirt, the second tier would be 6", the third tier would be 8", and the fifth & sixth tiers would be 7". You can eliminate the need to hem the skirt by using an wide eyelet trim for the bottom tier.
Now you're ready to start serging, or sewing (or in my case, both).
I used my serger to finish, and gather the length of my second tier to match the length of my first tier. I then attached the second tier to the first tier. If you're making a skirt with more than 2 tiers, then just continue gathering tiers to match the length of the previous tier, and attach them.
Now just sew the one seam to create the tube that will become the skirt. Create a casing at the top for your elastic, and sew your hem. I used my serger for seaming, and finishing the raw edges at the waist and hem. The only thing I used my sewing machine for was to sew down the casing, and the hem.