Do note that special moves and Distortion Drives inflict a small amount of damage when blocked, commonly referred to as chip damage. Also, keep in mind that throws, as well as certain unblockable moves, cannot be blocked.
It is very important to know if what you are blocking is a low, high, or overhead. Highs can be blocked with a standing block () or a crouching block (), but lows must be crouching blocked and overheads must be standing blocked. Do note that most attacks performed in the air (aerials) count as overheads.
Not only that, but you gain a nice Heat (meter) bonus every time you IB! Also, it can be tricky sometimes to know if your IB is successful; if your character flashes white and says something, you'll know you did it right.
Remember the chip damage you take when you normal block? Barrier block also negates that.
7. Throw Escape (B + C when being thrown): When the opponent attempts to normal throw you while you are in a neutral state (aka not attacking), a green exclamation point will appear, indicating that the throw can be broken. If you input the throw break command within this brief window, the opponent's throw will be negated and you will take no damage.
When the opponent tries to throw you during hit- or bock-stun, two purple exclamation points will appear. This is similar to the normal throw escape situation, except that you have much more time to react (almost half of a second). Be careful to always escape in-combo throws, as they do unscaled damage.
Finally, be aware that if you mash throw escape or if you are caught with a throw while attaking, you will be unable to tech (escape) it.