How to Securely Wipe Your Computer, Phone, or Tablet (September 10, 2020) — from legaltechmonitor.com by Jim Calloway

Excerpt:

Lawyers deal with confidential client information and we have a duty to secure that information. But it doesn’t matter who you are or how you use your technology. No one would want to donate, sell or give away a computer or phone without making certain your personal information is wiped. There is just too much information, like remembered passwords and saved text messages.

Today the respected tech website Wirecutter published an excellent guide How to Securely Wipe Your Computer, Phone, or Tablet.
You may want to bookmark this guide so you will have it handy when you need it.