Just a tip, I do this all the time but I donno if many of you do, I do this against people that do nothing but block. I got nothing against blockers but most of the people I play just sit back and wait for an opportunity (mainly the people that claim Blanka is the best character in this game).
But I will always say, it depends how you play the character.
ANYWAY. Do a swoop (my word for a dash jump), jump forward at the enemy and do a light kick, while still in mid air prepare the commands for the command grab on the directional pad, so that when you land the only thing left for you to do is press forward+high kick at the same time. I usually do this with Yamazaki and Vice (most of the time with Vice though). This wont give the enemy a chance to attack back after they’ve blocked if you were fast enough.