While it's not directly related to stay anonymous online, people who need anonymity/privacy shouldn't use Windows OS, OS based on Linux is the only choice.
1.Browse in private or in Incognito Mode
It only give privacy against people who might use your computer. Even if you use Incognito Mode, website can track you easily due to unique browser fingerprint.
3. Use anonymous email and communication
4. Hide your IP address using Proxies and VPNs
Good suggestion, but people should beware that :
1. Not all email, messaging, proxy and VPN provider who offer privacy/anonymity actually do it. Few VPN caught logging user's traffic and Telegram isn't encrypted by default.
2. If you don't change your surfing or browsing habit, someone could de-anonymize or track you, especially if you login to account with personal information when using Proxy, VPN or Tor.