Meta solution: As per the title, you need to think about "it". Four clues contain the letters "it" consecutively in that order.
If you remove the letters "it", you form four new clues that are alternative clues to four other entries in the puzzle.
"Bite (on)" (6A) -> "Be (on)" -> OCCUR (28A) ("Christmas will occur on Saturday this year.")
"Whiten" (31A) -> "When" -> TIME (20A)
"Finite" (50A) -> "Fine" -> PENALTY (47A)
"Gravity, for one" (22D) -> "Gravy, for one" -> SAUCE (1A)
Taking the first letters of these four entries, in order of how they appear in the grid from top to bottom,
forms the meta answer, STOP. This APTly relates back to the title, as you should want to STOP before making any rash
decisions and think about what you're going to do, before actually doing it!