To start off with. The daughter that I made this skirt for is a tall, skinny, Kindergartener. She just turned 5. In ready to wear she wears a size 4 or 5.
Sew (or serger) down the long sides of the skirt. Then fold over the top by and inch and sew it down, make sure to leave an opening so that you can thread your elastic through it.
Serge the bottom edge to get a nice clean finished bottom.
Then I picked out 3 fabrics for the tiers (I used the turquoise and cream dots, the purple geekly chic glasses fabric, and the cream geekly chic glasses fabric all are made by +Riley Blake )
I cut my strips for the skirt 6 inches wide. I cut 1 for each tier. To know how much you are going to need plan on 1.5 to 2 times more width than your skirt (this is a good rule of thumb for most ruffling). The fabric is 44 inches wide so it ended up being almost 2 times the width.
Sew the short ends together.
Finish off the bottom end of the fabric however you like with a pretty little hem. I did a rolled hem using my serger.
Then ruffle your tiers using your favorite method. This time I used a ruffler foot attachment to my sewing machine, but you could use the kite string method, or elastic thread, or the "shove the fabric under the foot and guess as you go" method. Whatever suits your fancy.
Now take your base skirt piece and your first tier for your skirt. Sew the first tier at the base of the elastic waist seam, making sure to not sew over that seam, but as close as you can get. Sew it down on the wrong side, with the tier pointing to the top of the skirt. That way it will hide your unfinished edge under the first tier
Now take a fabric marker and measure down 5 inches from your unfinished edge of your top tier and mark a straight line all the way around your skirt. Now sew your middle tier down using the same method from above.
Repeat again with the bottom tier. You should be sewing the bottom tier on about an inch above the bottom hem of the skirt.
Now you have a beautiful tiered skirt that your daughter will be sure to love.