One way to get a pattern is to find a picture on any site that gives how tall and wide, print off the picture,use a photocopier to blow it up to full size.
go to your local scottish shop and look at construction methods
be sure to increase the size of the gusset to about 3.5 inches or wider

then put it together in your head several times before you cut it out or start sewing

heres one I made using that method



this how-to might also help
http://www.xmarksthescot.com/forum/o...x.html?t=18903