There's a nifty new site by Scott Davis to practice RV with quick feedback: RV Practice Site
I tried the revised version just now and got this. No cooldown, just a quick focus on what the target might be, grab the mouse and draw. You can also enter text data if you like. Considering I drew it with my non-dominant hand, I'll take it.
It illustrates one of the kinds of sketching error Ingo Swann discusses in his seminal book - "Natural ESP: A Layman's Guide to Unlocking the Extra Sensory Power of Your Mind" (1987 and hard to find a copy). I'll be presenting on this subject at the Applied Precognition Project Conference/Webinar/Workshop in Las Vegas starting June 19.