The biggest tip that helped me was what no-hit runners do: hold block the entire time and quickly tap it whenever you need to parry. If you miss the parry timing, you're still blocking so it won't destroy your health. Blocking also reduces your fatigue bar substantially faster so it's win/win to just hold it the whole time you're fighting someone.
That, and learning that EVERY attack can be deflected as long as it doesn't have a red kanji beforehand. There's no need to ever dodge unless you see that symbol first.