First Check you label make sure your items is Washable .
Hand wash you skirt in Cold water and Rinse well.
 
Then Rinse again with 1 ounce Stay Flow Starch in 3 gallons of water.
Set your washing Machine on spin to spin the water out.  Add to or decrease the starch as needed.
Now You will need these items. Twine and Scissors.
Cut small pieces of twine to tie around the skirt at the top, and each tier and at the bottom.
Hold the skirt at the waist and accordion style gather the top and taking the skirt in your hand run you hand down the skirt keeping it in your hand at all times.
Now at the top near the waist band tie the first Knot around the skirt, Move to the next tier and do the same, All the way down to the very bottom and tie that too.
For non tiered skirts follow the same instructions, except you will only tie at the top by the waist band and at the bottom.
Once you have done this hang the skirt up to dry.
Let the skirt hang like this for 24 hours.
The outside of the skirt will most likely be dry, but not the inside.
So take your scissors and carefully snip the twine leaving the twin at the top intact.
(Take your time or you could snip the skirt)
Now hang again for 24 hours to allow the inside of the skirt to dry. Remember non windy area or you will blow the wrinkles out.

Now you will have a beautiful skirt every time you wash it.

***  I just figured out a way to tie the tiers that to me is much better than twine.     I am now using Plastic bags.  Like the ones you get from the grocery store.   They make the areas that are tied less noticable,  Than when it is tied with twine***