Are you aware of any guidelines or rules of thumb for including actual people/places/events in works of fiction? I know this is commonly done in historical fiction, but what about works set in the present or recent past?
If there are no guidelines, what are your own thoughts on this practice?
Places and events aren't too much of a problem, it's people that can get you into trouble. The main thing you need to worry about is libel. If the person is still alive and they feel that what you've said about them has damaged their reputation, they can sue for libel. Public figures, celebrities, politicians, etc. are generally safe to write about, unless they can prove malice on your part. You can read more about it here and here.
Where you really get into trouble is if you fictionalize characters that you know on a personal basis (like neighbors or family members), and they are recognizable to themselves and to other readers, and they don't like it, they can sue. Or possibly never speak to you again. This can be a problem in memoirs, where an author's story is tied up with the stories of the people in their lives. It's a fine line and has to be handled carefully.
If you're going to include a historical person in your fictional piece, you should do enough research that you can portray that person accurately and fairly.
I guess my bottom line is, I wouldn't want someone writing about me without my permission and approval of the text, so I extend that courtesy to others. If it's a quick reference to a public figure like, "Debra had a crush on George Clooney..." or even Debra having a brief conversation with George, I'd be fine with it. But if Debra was having an ongoing relationship with George, that I wouldn't do without George's signed and notarized release form in my files.