There is a procedure for installing the cam, timing chain and gears correctly in the manual. That is all you require for a street engine.
Racing is another matter and benefits can be gained by setting up the camshaft's timing precisely. First you have to have specs for your cam. Then you need to have some way of adjusting the cam to different positions. You can machine different keyways into the cam sprocket, make up offset woodruff keys or make a custom adjustable sprocket. Now you can partially assemble the engine and use a dial gauge and degree wheel to figure out what you have. Adjust as needed.
The trick is knowing what it is needed!
I advanced the cam 2° on a tricked-out Ducati single using offset woodruff keys. On my Europa, only mildly-modded, I just put it together as per the manual.