Perfect is a high bar. It all depends on the product and target market, but there are time-tested guidelines for effective ad copy:

Focus on benefits over features. Answer "what's in it for me?" from the customer's perspective.

Speak to a specific pain point using the customer's own language.

Create an emotional response first, then provide rational justification.

Lead with the most compelling hook.

Eliminate every unnecessary word.

End with a clear call to action.