Some of this is a recap of what others have said but thought it would be good to bullet them:
- TCLOCS (always and especially with a rider): Tires, Cables, Lights, Oils, Chassis and Stand.
- Suspension adjustment for additional weight (this is huge)
- Wide stance with feet, and good grip on handlebar
- If you have a backrest that bends forward, bending it forward under your butt is not only a courtesy but makes the it easier on the rider (hate to see someone trip on it and go over)
- have rider step up on the bike like going up a set of stairs which means they lean into the step and not try to pull the bike to them. If they do it right, you will not feel much shift as their body will quickly transition to the center of the bike.
- Make sure rider looks over your shoulder in the direction of the turn/curve. DO NOT have them move or shift. Just a casual peek over the should is enough
- With the additional weight, is is imperative when entering a turn/curve to slow before the turn, look at your exit point and roll up on the throttle through the turn/curve. (just ask the scraped up riders who did not heed this advice on the Tail of the Dragon - 318 curves in 11 miles)
- Work the friction zone with the clutch and give it a bit more throttle on very slow riding IE parking lots and u-turns.
- Lastly, have fun!