How to avoid the “divide by zero” error in SQL?

I have this error message:

Msg 8134, Level 16, State 1, Line 1 Divide by zero error encountered.

What is the best way to write SQL code so that I will never see this error message again?

I could do either of the following:

• Add a where clause so that my divisor is never zero

Or

• I could add a case statement, so that there is a special treatment for zero.

Is the best way to use a NULLIF clause?

Is there better way, or how can this be enforced?