As mentioned, many different formulas. Personally, after doing quite a few "run ins", my basic rules are:
Use a higher gear so increased load, whilst avoiding boost
Higher rpm (~5500) ok but avoid doing so until warm & without boost
First few hundred kms, I take a few very uphill routes (springwood rd late night)
Don't let the car sit & idle for extended periods of time
As MCT said, avoid long boring hwy kms, but when forced to, I tend to slow down a bit so I can load up over & over again
I don't try push an aggressive tune until 5000-10000 km, but I still get a relatively high hp tune after 500-1000km (my current motor did a lazy 300rwkw @ 18psi after ~1000km), upto 8500 rpm
This is for a street car & motor that I want to last as long as possible.