If you are more comfortable doing this type of work in Adobe Illustrator Photoshop or Adobe Photoshop, you could also start in those applications and import the Illustrator or Photoshop files directly into Expression Blend.
Michael S. Scherotter
Michael Scherotter is a Media Experience Evangelist for Media and Communications with Microsoft Corporation based out of San Francisco. As part of Microsoft’s Communications Sector evangelism team, Michael focuses on interactive client solutions for communications and media companies. Educated as an architect, Michael Scherotter brings a sense of creativity and design to synergistic software development and throughout his 14-year career in software development, Michael has specialized in combining software in innovative ways. He architected and developed desktop CAD applications for Boise Cascade Corporation, managed software development teams and engaged with partners as a Business Solutions Architect at Mindjet Corporation, Michael has a Bachelors of Architecture and a Masters of Architecture specializing in Design Tool Development.