In ours, at 1100rpm you check engine temps and pressures are in the correct range.
Then you check that the engine keeps running on each mag in turn.
Then increase rpm to 1800, check temps and pressures again.
Check each mag in turn, that the drop in rpm does not exceed 150rpm, and that the difference between the two drops is less than 50rpm.
Have a last glance at ts and ps and reduce to idle. Check correct idle rpm (750ish), and back to 1100rpm.
There's some other stuff to do with cycling the prop., but that's not really part of the power check.
OOps, backpacker beat me to it!