This is how I figured out how I needed to cut my fabric. She has a 17 inch waist (1.5 x her waist length) and I wanted the skirt to come down between her knees and ankles (I'll try not to be confusing) so I held it up to her and came up with 10" length for the skirt and 2 5/8" for the top band.
What you will need to make a skirt 6-12 months size:
2 pieces 15 1/2" x 10" for skirt front and back
2 pieces 15 1/2" x 2 5/8" for top band
2 pieces 5"x5" for pockets
2 pieces 1 1/2" x 36" for the bottom ruffle
To get started I traces out the cut for the pockets ,fake pockets ;) that is, I used a coffee mug that I placed on the top left and right side of the skirt front and cut both sides out. Then press the cut outs under. When I did this I set my iron to a lower setting and placed a piece scrap fabric over the suede leather as not to hurt the it. Next pin in place the back of the pockets (5"x5" pieces) behind the cuts you have just made. I used a double needle on mine. Then take the ruffle pieces and hem them and run a gathering stitch across the top of both pieces. Gather them and pin in place on both the front and back skirt pieces. Stitch in place.
I then did a top stitch on the front side of skirt just right above the ruffle, see picture just below.
Next sew the front and back pieces together. Then your going to sew the two waist band pieces together. Then make your casting for the elastic. I pressed the waist band down 1 1/8" then stitched it in place with leaving a 1" space open to run the elastic through.
Then attach the waist band to the bottom of the skirt. I also pressed the band out and did a top stitch just below the stitching for the casting. Last run your elastic through and stich it, sew the 1" space that was left open closed and your done!