This has been covered extensively, and there are many different opinions.
These are just my opinions: From day/mile one, make the engine work, do not idle it for long periods of time, bring it up to temp, then make it work. The warm up is important. Cool down is too, don't shut it off immediately after a hard run, ride it at a normal speed for 3-5 minutes, then pull in and shut it off.
I say "ride it like ya stole it", but take that with a grain of salt.
Make it work is the best way I can describe it. Change gears a lot, work the engine up and down, do not decelerate for long periods of time, some is good (oil in the cylinders), too much is bad. The oil in it from the factory has additives, use it til 750 miles like they say. Put and additional 1500 miles on it and then switch to full synthetic, the full synthetic can be too slippery to use right off the bat, and cause needle bearings to not rotate causing a flat spot on the roller.
I also would suggest your first ride be longer than 25 miles, 100 would be good. Watch the temp gauge. It should be just a bit below the middle mark, that is the most common I've seen.
If you can get them to not ride it, that would be good, if they must, tell them to keep the miles less than 5.
The engine has already been run in on a dyno from the factory, there should be a dyno slip with your bike, it will give you HP at the crank.
If anyone disagrees with my opinon, keep it to yourself or state your thoughts on it, I'm not interested in a big debate.