Exclamation points are used at the end of vigorously energetic or forceful sentences, such as those expressing:
Example: The food here tastes great!
Example: Be careful!
Example: Back off!
Example: That's incredible!
Example: Oh no! They're here!
Example: I have an IPad!
Example: I like you! I really do!
8) Loud noises:
Example: Zap! Ka-Blam!
9) Strong Commands
Example: Stand down!
While exclamation points could be used as a tool for expression, please remember though that they are not recommended to be used in your IELTS writing module.
Here's a video by Paige Carrera discussing when an exclamation point could be used.
Attribution to Rebecca Elliot and her book Painless Grammar and to Paige Carrerra
Other punctuation marks:
Parentheses, Brackets, or Dashes