YouTube is the second largest search engine. And YouTube videos appear in Google results. Two search engines, one piece of content.
1. Title = Keyword + Hook
Your exact keyword in the first 60 characters. Then a hook. "How to Fix a Leaky Faucet — 5 Minute DIY Fix." Not "Plumbing Tutorial Part 3."
2. Description Matters More Than You Think
First 2 lines appear in search. Write them like a meta description. Include your keyword. Include a link to your site. 200+ words total.