The earliest forties fashions were an echo of the gorgeous 30s. Shortly after, fabric rationing started with World War 2, so the styles became much more simple, without the accoutrements seen before or after the war -- hemlines were slightly higher, and bows, ribbons and the like simply disappeared. Men's patterns of that era are very scarce, as so many men were overseas. After the war, hemlines dropped, and there was lots of gathers and shirring to show off the female form. All of this was simply an introduction to the New Look, introduced by Christian Dior: very nipped waists and hugely full, almost circular skirts that followed fashion into the 50s.
Browse around -- whether you want to be Rosie the Riveter or Hollywood glam, you'll find a pattern for the style you need.