Just don't thrash it , let it work through the rev range, avoid limiter bouncing, ( which is quite difficult in first gear in a manual) and remember that on a turbo to let it spool before sticking your foot to the floor, try to avoid long journeys at a constant rev range,and above all do not feed it after midnight....

If you are going to keep it more than three years it's worth some TLC
The running in period is not just for the engine it's for the breaks, the running gear, suspension, and so on,
I have tuned race engines in the past which operate at the most efficient when brand new,
However shelf life is shorter, but if you ran them in they would last longer
for a cost of power, the gains are very insignificant and to a road car
It really is more about the car bedding in not just the engine,