Here's my method (two cents )
Warm it up to operating temp (at a high idle if new cam to ensure enough oil) and then drive it like you stole it!

Have watched hi-po race motors get built, put on the dyno for maybe half an hour of variable rpm to run in the cam and then straight into full power pulls.
Modern machining techniques, materials and equipment mean tolerances etc are so much better and the take it easy isn't really necessary.

I know each to their own but have only lost one motor this way (actually lasted 1000km and popped at a sprint at full noise down the back straight), which was actually due to the fact had used a secondhand piston and it was a touch undersized. Motors also just seem more free and seem to develop more power (SOTP ).