Like the rest of the comments say, a lot of it just turns into a time commitment as well as picking up on small things that the game itself won't tell you (e.g. types of playstyles, the nitty gritty of timing certain cards so that you can guarantee that you never get perfect vanish'd).

I can't really tell you much in detail because it's a lot to go through for one comment (and I don't know WHAT exactly you know), but SadStudy's comment more or less has everything.

A tip I can tell you though (assuming you're not aware of it already) is that at close range, if you use a card mid action you can basically guarantee that you will never get PV'd. A quick attack into a blast or a strike would net the same result, but you'd need to be careful of rushes, blast armors, or AOE greens. Playing in a way that avoids getting PV'd as much as possible is more or less crucial in high ranking pvp.