Panels from Star Wars: Knights of the Old Republic #28 (May 2008), script by John Jackson Miller, pencils by Scott Hepburn, inks by Dan Parsons, colors by Michael Atiyeh, letters by Michael Heisler
Panels from Star Wars: Mara Jade #4 (November 1998), script by Timothy Zahn, pencils and inks by Carlos Ezquerra, colors by James Sinclair, letters by Michael Taylor
Panels from "First Impressions" in Star War Tales #15 (March 2003), script by Nathan Walker, pencils and inks by Kilian Plunkett, colors by Dave Nestelle, letters by Steve Dutro
Panel from Star Wars: Jedi: Aayla Secura one-shot (August 2003), script by John Ostrander, pencils by Jan Duursema, inks by Dan Parsons, colors by Brad Anderson, letters by Sno Cone Studios
It's clear that Al Williamson and Carlos Garzon had the script and decent photo reference of the actors and characters when they drew the comic book adaptation of The Empire Strikes Back:
Panels from Star Wars #42 (1977 Marvel series) (December 1980), script by Archie Goodwin, pencils and inks by Al Williamson and Carlos Garzon, colors by Glynis Wein, letters by Rick Veitch
But they might not have had any notes on character height or any photos of Yoda and Luke together:
Panels from Contemporary Motivators: Star Wars (Pendulum Press, 1978), script by by Linda A. Cadrain, pencils and inks by Charles Nicholas
Page from an "easy-to-read" adaptation of Episode IV. Notable for its early appearance in the Star Wars Universe of Joel Robinson, Tom Servo, and Crow T. Robot: