A bunch of “rules of thumb,” via Google, natch.

• Japanese Etiquette
• Bars: A patron’s guide. || kuro5hin.org
• Rules of Thumb for Building Churches
• SIRC Guide to flirting
• Rules of Thumb for Evaluating Pet Stores
• Chess Rules of Thumb - USCF Sales
• Etiquette for Unmarried Interactions
• RULES OF THUMB FOR OFFICE SPACE PLANNING
• Rules of thumb for spatial data — Brian Klinkenberg
• 21 Rules of Thumb – How Microsoft develops its Software
• Color Rules of Thumb
• Heuristics for User Interface Design
• Rules of Thumb for Software Internationalization
• Rules of Thumb for Selling Remote Controls

The best rule of thumb I always remember is from a book of the same name that’s probably out of print. I think of it every time I skulk around the house acting like a dissatisfied crank:

If you don’t know what you want, you probably need a nap.

Got a good, (non-dirty) rule of thumb to share?

Update 2005-02-16T11:11: Sharp-eyed GH noticed the wonderful Rules of Thumb books are available used on Amazon. Awesome.

• Rules of Thumb
• Rules of Thumb 2
• Never Trust a Calm Dog: And Other Rules of Thumb

Check out the comments for interesting background from the books' editor.