I made a bright pink pettiskirt for my niece for Christmas. She's almost one and a half, and it turned out to be a little big on her. Plus, I was in a rush to make it and I may (or may not) have made a few mistakes along the way. But at least she can grow into it! And it'll fit her for a while because I made the waist adjustable with elastic and ribbon.
Here's an image I made of it dissected so that you can understand how it goes together and how to make your own. Also, try only making 2 chiffon tiers instead of three.
It takes a while to sew because it's so much fabric and you have to gather all of the fabric at some point. So give yourself plenty of time!
While I didn't get any pictures of her wearing it (or my other niece who is 2, who it actually fit), you can still see how fun it is.
This skirt is supposed to be 2 layers. So you essentially make the same skirt with all this fabric twice, then sew them both to the satin at the top. I only made one layer (because of time constraints) but I really wish I'd been able to do two! It's still super cute as it is, but twice the ruffles would have made it a little fuller.
If you can find it in 4-inch or 5-inch wide spools of non-fray chiffon, get it. It's easier than cutting all of it. If you can't find it that way, I figured out a pretty good way to cut it. Carefully accordion fold and pin the selvage edges together, so that your folds are only about 2 feet wide. Lay the fabric on your cutting mat, and straighten it out so that it's as square and neat as you can get it. Starting from the bottom (where the pins aren't) place a yardstick across the fabric at the width it needs to be cut, and while you firmly press the yardstick down to hold the fabric in place, use a rotary cutter to slice through all the layers, making all the strips of fabric you need. It can be a little tricky, but it saves a lot of time.
A serger works way better than a zig-zag or other finishing stitch the average sewing machine makes. Finish all the edges before you start gathering and stitching tiers together. Otherwise you'll have a mess of frayed edges and you can lose some of your fabric width because of it.
Mark the halfway and quarter points of each tier so that you can match it up to the next tier's half and quarter points, keeping your gathers relatively even.
For additional tips and a tutorial, check out this one. I based mine off of it. It's pretty well done and quite thorough!