> Hover over links and then type the URL into Google rather than just clicking on it.
The link is irrelevant, and in many companies will be a huge URL full of "random" characters that goes via a service that can block the link if it is later detected as bad.
The way to verify links it to click the link, then when the redirects have finished and you are on the login page you check the URL of the actual page to confirm it is Google/Microsoft/etc before entering your credentials.
Also, if you get an unexpected invite from someone you don't know, you ask who they are? And if impersonating someone you know, you ask that person what the unexpected meeting is all about...?
We have a group of users who regularly receive files unexpectedly from industry contacts. Their instructions are to phone the sender before opening. Whilst I am not aware of another companies IT department officially giving this advice, it is something that once our users started doing it many of their contacts started doing it as well because people talk, and many have replied to an email asking if it is legit and gotten a "yes all safe" reply followed by "no, my account was compromised, don't open"... And they fear for their jobs enough to have started doing this without being told.