This is one of my favorite skirts (and my sister’s favorite to borrow). It’s not the quickest sewing project, since you have to sew each seam twice – once to put in the piping and again to actually make the seam – but it’s worth the extra effort. These are the pattern pieces:
To add piping to a seam, first sew the piping to one side, placing it on the right side of the fabric with the decorative bit facing in. Sew along the edge of the raised part – sewing on the raised part looks fine, and sewing too far back does not, so error on the side of keeping too close. Next, pin the second piece of fabric in place with the right sides together. Sew along the seam, catching the piping in it. You can feel where the piping is under the fabric – use this to line up the seam so you sew as close to the raised part as possible. You may need to sew over some parts again if it looks uneven.
First sew together the bottom and middle pieces of the side panel. Next add the pockets and sew the piping to the sides. Sew the front and back to the sides, then add the piping to the top and sew on the waist band. Finally, add the zipper to the back and hem the bottom.
To add the pockets, sew the piping to the top of the pocket, then add the top of the lining. fold the lining back and top stitch so this edge lies flat. Sew the lining of the pocket to the back of the pocket (the top piece of the side panel). Add the piping along the long side seams of the assembled side panel to hold all the pieces together. You can sew the pocket into this seam (I did) or leave it out.
To add an exposed zipper, finish the edges of the fabric so they won’t unravel by running a zigzag stitch along the edge. Place the zipper on top of the right side of the fabric so the fabric and the zipper overlap by ⅝ of an inch. Sew from the top of the zipper to the bottom ⅛ of an inch from the edge of the zipper. Repeat on the other side.
The piping stiffens the fabric so you need to add a facing to hem. Sew the facing to the bottom of the skirt. Turn under the edge of the facing, and carefully sew it to the inside of the skirt like you would an ordinary hem.
Edit: there are more photos of the process of making this skirt here.