One mind-blowing experience with West End Games' Star Wars: The Roleplaying Game last millenium, if I remember correctly, was a sample script between a GM and players in which the eager heroes exclaim, "We attack the Star Destroyer!" The GM attempts to make sure they understand what they're undertaking and draws a large triangle taking up most of a sheet of paper. "This is the Star Destroyer," the GM says, "and this . . ." – adding a tiny dot next to the giant triangle – ". . . is your ship." The players immediately respond along the lines of, "Evasive maneuvers! Let's get out of here!"
As a GM or player in an RPG, I'm often acutely aware of my own artistic failures. I have the keenly honed drawing abilities of someone who decided the smartest path was to devote his life to writing. Still, I'm more than willing to use my lackluster artistic skills to convey what I can. And I encourage you to do so, too.
Sketches (even poor ones) can convey scale: is a character smaller or larger than average? They can help players understand a default emotional state; if the initial sketch of Queen Evokateve has her with a large smile (or maybe a frown with the "angry eyebrows" instead), then the others at the gaming table can quickly understand her apparent mood without asking. Similarly, a player whose PC is portrayed with a giant sword is probably trying to emphasize an important aspect of that hero.
You might even surprise yourself when you make a quick sketch. Once, when trying to denote a prince to my players, the first thing I drew was the crown. This was primarily to get the rest of the face right. But I realized, after a moment: "Does this mean that the sign of his regal power is the most visually striking and important element of him?" And, in that moment, I decided: Yes. Yes it was.
Sure, your efforts may be little more than glorified "stick figures" (or even not-so-glorified), but they're still useful as visual elements. In a world where evocative visions are trying to be conjured with numbers and words, a little bit of visual pizzazz often improves the experience.
My penchant for verbosity means that I have more to say about this, but my editor is encouraging me to split this into two posts. Until then, keep sketching, no matter how less-than-professional your efforts may be.
-- Steven Marsh