When writing an introduction:
Think about the inverted pyramid as a symbol for an effective introduction.
Start with a "hook” to grab the reader’s attention.
Transition from the broad idea introduced by your hook to the specific purpose covered in your paper.
End with your thesis statement.
Ideas for a “hook:”
Question: Start with a question that gets your audience to think about your topic.
Anecdote: Everyone loves a good story. Make sure it's relevant to your topic.
Definition: Start with a clear definition to build a foundation for your argument (be careful - this technique can be a bit dull and overused).
Quote: Open with an interesting or surprising quote.
Misconception: Challenge your audience's assumptions.
Contradiction or paradox: Reveal the complexity of an idea.
Statistic or Fact: Surprise your audience with a curious or little-known fact.
(from Azusa Pacific University’s Writing Center)
When writing a conclusion:
Think about a pyramid as a symbol for an effective conclusion.
Start by restating your thesis using different words.
Summarize your argument.
Go broad by giving practical implications or broader application of your argument.
Why is your argument important? What are the potential implications of adopting/not adopting your viewpoint? 
What theme have your introduced that you can revisit? Did you begin with an anecdote for which you can provide an ending? Can you emphasize a completion to the issues or ideas raised in the paper?
Can you propose a solution to a problem or a question needing further investigation?
Write your introduction and conclusion after writing the body of your paper.
Academic Skills, University of Melbourne, 2020.