As DG indicated, ebay's suggestions were to include the material/fabric in the title. Which I have now done. Re the 'cookie pan' - I just used the title on the actual item. But I have now included biscuit in the title as well.

I had a chuckle at your suggestion for using the term long instead of maxi. I always used to use long, but since changing to maxi have sold heaps more.

But it does seem odd that out of 50+ skirts listed, ebay wanted me to add fabric to just one (which was rayon in this case). Some of my other skirts include fabric in the title (if I think it important enough) such as linen or cotton, but it seems if there is any hint of a fabric blend, or polyester, then this isn't relevant in the title.