There are two options here.. actually, there are infinate options, but that falls into the 'creativity' category, and I can't do all of that for you.

So anyhow, there are two main techniques for making the spacegirl skirt (name coined by a seriously cool person I work with, who wanted insrtuctions on making one for a Halloween costume.) This will work best with a fairly stiff fabric.

The first is a simple circle skirt.. literally, cutting a circle out of fabric, and putting a waistband on it. The second is a lot more adaptable, and probably will look better, too. It's a skirt cut in gores, flared out as much or as little as you'd like.

For the first version, you need a square of fabric big enough to make a big circle. If the fabric you want to use isn't big enough, just sew two rectangles together, and pretend it's one big square. We'll be getting into a bit of math in a second; it's not that hard, and you'll finally have a use for some of those classes they forced you to take in highschool. (If you REALLY don't want to deal with numbers, get a lot of cheap fabric you don't care about, and keep trying until you get it right.)

• First, you need to measure your waist. Write it down somewhere.
• Second, measure your hips. Add 2". Write that down, too.
• Third, determine how long you want the skirt. Add 2" for hem and seam allowances. Write that number down as well.

Now, we all know the human body is NOT perfectly circular. Pretend it is for this.

You need to figure out how big the circle needs to be. To do this, find the radius of your waist measurement (use that number you wrote down as the circumfrence.) Then, add the length you want for your skirt. This is the radius of the circle you want to cut. There is a really good page on geometry regarding circles here.

Now, you need to figure out how big to cut the hole in the middle. No, the waist radius won't help you out here. Use the hip +2" measure, and figure the radius of that. This gives you a bit of ease to get it over your hips.

Look towards the end of this page, and follow from where I say "both skirts" for instructions on the waistband and hemming this things.

The second version is a little less math-intensive, but requires a bit more work.

First, take the same measurements as needed for the first skirt.

Now, divide the hip+2" by 6. Round up if you need to.
Draw a line that length, +1" on a piece of newsprint or plastic tablecloth (this is going to be your pattern. Pick something big enough.) In the center of that line, draw a perpendicular line however long you want the skirt, +2". (this is that original 2" I asked you to add.)

Now, draw a line the same length as that perpendicular one angling out from either side of the hip-derived line. Keep the angle the same on both sides. (If we're going highschool math here, a protracor would help!)

Curve a line connecting the three at bottom. Try and match it (but very, very slightly!) at the top. This is your pattern for all six pieces.

The pieces of this pattern have a 1/2" seam allowance built in.

Cut six of them, and sew together.

For both skirts:
Cut a long rectangle that is your hip measument +3" by 4". This is going to be the waistband.

Sew the short ends together. Pin, right sides facing each other, the skirt and waistband, and stitch.

Now, fold the waistband in, so the top fold is about 1" from the seam between band and skirt. The flap in back should hang down lower than that-there seam. This is what it's supposed to do.

Now, fold the raw edge of the waistband (in other words, that bit you just folded in) in again, so the raw edges of the seam and the waistband are all enclosed. Pin.

Lay the skirt so you are looking at the correct side. Now, stitch carefully about 1/4" above the seam where the waistband and skirt join. This will keep all of the ragged bits safe inside, where they can't unravel. Leave a 2" gap, though, in this stitching. You need this to put the elastic in.

Cut a piece of elastic that is 1" shorter than your waistline. Thread it though the casing you've made (safetly pins are good for this, though I've been known to use paper clips, crochet hooks, backwards needles, and just about anything else that comes to hand) and secure it. (I usually do a |X| sort of stitch.. go up, down, up, diagonal down, up, down, up, diagonal down.)

Now, trying not to catch the elastic, close that little 2" gap you left.

You're nearly done. I promise.

All that's left is to hem the skirt. Yeah, I know. Hemming sucks. Get used to it.

If you're running short on time, heat 'n' bond, stitch witch, or any of those other no-sew iron-on tapes will work for hemming. I personally don't care for them, but I'm not about to stop anyone who likes them from using the stuff.

Please keep in mind that these instructions work for me, and that your milage may vary. If you get totally stumped, email me, and I'll try to help.