Joe Johnston was a designer and illustrator at Lucasfilm in 1976, and he did a lot of work on a little movie they made called Star Wars. He later went on to become a director, bringing us The Rocketeer, Jurassic Park 3 and Captain America: The First Avenger.
In 1978, attempting to squeeze even more money from the film, Ballantine published the Star Wars Scrapbook… featuring all of Johnson’s original sketches. Here’s some select pages from the book, for your enjoyment. It’s out of print, but you can probably find a fairly cheap copy on eBay.