A very good resource for aspiring writers

Rule 3. Avoid overusing there is, there are, it is, it was, etc.

Example: There is a case of meningitis that was reported in the newspaper.

Revision: A case of meningitis was reported in the newspaper.

Even better: The newspaper reported a case of meningitis. (Active voice)

Example: It is important to signal before making a left turn.

Revision:
Signaling before making a left turn is important.
OR
Signaling before a left turn is important.
OR
You should signal before making a left turn.

Example: There are some revisions that must be made.

Revision: Some revisions must be made. (Passive voice)

Even better: Please make some revisions. (Active voice)