Correct: take for granted means that you have come to expect something as if it had been granted to you.
Incorrect: take for granite

Correct: spit and image means made of the same stuff (spit) and having the same appearance (image).
Incorrect: spitting image
[I have been guilty of this one.]
This is another one of those phrases that has degraded over time:
spit and image to spit an’ image then incorrectly to spittin’ image and spitting image

Correct: by accident
Incorrect: on accident
But Leslie Barratt of Indiana State University did a study showing that on is more prevalent under age 10, both on and by are common between the ages of 10 and 35, and by is overwhelmingly preferred by those over 35.