I shoot Easton axis arrows. I find the "spine" of the arrow prior to building it. Like a fishing rod builder would find the "spine" of a rod before building it. I flex the arrow against my thigh and roll it while flexed. Doing this you can feel it get stiff and weak as it rotates. This is the same thing you find with Radsav's turn the knock method.
I then orient the stiff side so that all arrows are the same in this regard. I put it to the cock feather, but that don't matter as long as they are all the same.
Even after all this fun, some arrows just wont play nice. They get relegated to practice arrows and blunt arrows for trashing trying for grouse.

I've also found that if an arrow impacts something hard, like missing the bales and hitting a 4x4 ect.... that the arrow may then no longer group with all the others even though no visual difference can be seen. Again, its a blunt arrow after that.
I tune my bow using field points and some Magnus 2 blade broad heads. These broad heads are like sails, so if they hit with field points than any of the small profile blade heads will hit as well. I shoot a Hoyt so get to do all the cam lean tuning, ect... Its a process, but once done, its oh so nice.