I really like Robert Best's illustrations. He illustrates Barbie dolls. He uses a lot of feminine colors and lady-like silhouettes.
I like how Cedric Rivrain uses black and white on the model then uses bold colors for the garments. This really emphasizes the garments and grabs the viewers attention.
Kate Spade's illustrations are feminine,classic, and fun. I like that she adds props to her illustrations to give her models more life.
This is an illustration from Elie Saab's Fall 2012 couture line. I loved the soft, pastel colors in the line and I love how they are translated onto paper.
This is Jerry Seguin. It looks like he uses water colors, which I am a huge fan of. I have tried to uses watercolors to achieve looks like this.
Joseph Larkowsky's models are unusual and almost look distorted. I like that this allows the viewer to really focus on the garments.