1. Install uBlock Origin extension. (If you’re not from US, check its options to turn on ad block lists for your country)
2. Do not install any other extensions ever! (exceptions: 1Password, Google Arts & Culture).
3. Create separate “people” for different activities: e.g. home, work, browsing sketchy websites. (Click on avatar → Manage People.)
4. If you want to turn on sync, set up encryption passphrase. It’s a separate passphrase from your Google account — your sync data will be encrypted locally with it before hitting Google servers.
5. Disable saving/auto fill of passwords, payment, and addresses. (https://twitter.com/Sc00bzT/status/1085521985017466881)

That is all (for now).