Just start thinking about the battle in the 2 seconds of leisure time you get after getting knocked away [you'll most likely lose that match, but win the next].
However, like another topic said, put it into your subconscious, so if another mindgame like that ever happens again, you'll know how to stop it the next time.
Usually, a trick will only work twice on me before I figure out its counter the third time.
First time, I usually don't pay attention to it, Its like any other random move.
Second time, I get annoyed, I think about it as the match continues [multitask].
Thrid time, I counter it, apply it to future matches, so it does not happen as often again.
However, this really only applies to friendlies, where there is less pressure [never been to tournaments before, so I can't say how hard it is there]. Also, some tricks are harder to beat or find than others, those you need to be careful of.
Often, in the past, I would try grabbing my brother, he spot-dodges, I sidestep, repeat, until he finally gets me. It always ended like this for me, mostly since either his char was faster, or he was faster. I never noticed this until after thinking for a while. Now I know that as soon as that happens, get the heck outta there, either through wavedash or jump.