I don't know anything about that video, but I can tell you from experience that it's tough for any video to cover more than the basics. Every head is different on what works best, and can't say what works for one does the same for all.
I've also found that a little is better, so don't go crazy porting your heads, or you risk having them not work better, or even ruining them.
Gasket matching is good, and cleaning up imperfections is also good. Some factory heads have a reputation for having the same imperfections in the same places, so if you know someone who's done much with your type heads, talk to them and see where the bad spots are. I know the newer SBC smog heads have some horrible looking casting flaws hanging into the intake runners when compared to aftermarket, or older better heads.
Stay away from the bosses around the valve guide areas in the runners! You can easily ruin heads grinding around that area! Get some machinist bluing and you can mark out the intake gasket to match them, and then just gradually blend, and not go too far. If you have an intake already, check it also against whatever gasket you will use, and match it to the same.
On the exhaust side I usually just clean things up, as I haven't found as much increase in performance with a lot of exhaust port work, where intake work seems to garner more for me.
Should do all your work with the heads disassembled too! Don't take a chance on damaging a valve stem, or getting grit in places you don't want it. I do all my porting on stripped heads, before any valve job or assembly is done.
