Yeah Zane *****. Easily the best Ganon to ever grace this universe. No matter what anyone says, I'm going to say that it is always MOSTLY prediction, simply due to Ganon's lack of agility/speed. You normally have more than enough time to chase a tech (unless you uthrow a fastfaller at mid% and they DI away AND techroll away, then you basically have to dash and SHFFL a fair immediately), and this is time when you can get sorta fakey with your moves. Dasing, walking, and jumps mostly. The thing is, some people have already chosen which way they are going to tech as soon as you grab them (lawl, but I've seen this happen A LOT), so that leaves you with a basic game of recognize patterns, predict, and punish. For those that pay close attention though (high level players or an above average player that is used to playing a good Ganon or any other character whose game is heavily based on techchasing), you can do little things to fake them out (make them do what you want them to do) during that small window of time you have.
If you dthrow a fastfaller and they land right in front of you, you can do stuff like, fulljump early to make them think you are ready to punish a tech in place with dair, and as soon as you see them roll, hold forward and fair. Or you can jump backward and act like you're going to stomp a techroll behind, and just fair a tech in place. You can also do something like, dash backwards if you dthrow a fastfaller at mid% when he DI's behind, then jump back to punish a techroll forward (roll back to where you where standing initially) with dair.
Those are some of the things that I do anyway, when I get a grab on someone like pp or lozr.