I have broken in a new turbo before...as well as after a rebuild.
Warm it up in the garage...make sure no leaks. don't let get very hot.
Warm up well in parking lot.
First bit of riding, stay on trails and do some light throttle with quick loads (1-2 sec)...let it pull into the powerband and then back off. Get motor to temp. Shut down and check out. Let it completely cool down (15-20 min break).
Next ride a bit harder...warm up well...more throttle, still on trails or flats. Don't sustain any throttle setting too long. Get it hot again. Ride a bit more. No hard or sustained pulls. Stop, check out. Let cool.
Next ride even harder...warm up well...maybe some short, easy 2-3 second long pulls at 3/4 to full throttle. Stop, check out. Let cool.
Next ride full warm up...get on it. Longer pulls. Ease into heavier motor loading. Ride forever from there.