You always need an introductory sentence which ends with a colon.
If the text after a bullet point is a complete sentence, it should be punctuated like a normal sentence.
What to take on holiday:
- You will need sun cream to protect your skin.
- Don’t forget to take your passport.
- A credit or debit card to give you access to money.
If the text after a bullet point isn’t a full sentence, it shouldn’t be punctuated.
What to take on holiday:
- sun cream
- passport
- credit or debit card