It doesn't matter if you do all the error checking in the world, or if you have the most beautiful graphics, if your site or application design isn't usable, it's not going to do well. Get input and advice on usability and user interface issues here.
Assuming you have a dynamic website, where components of the "chrome" (menubars/ footers/etc) are pulled from the database; which do you prefer for the "database down" error page?
1. Simple "chromeless" page, ie obviously not the general site layout. Probably black text on white background, slightly larger, etc.
2. Normal page layout, with "Unavailable" place holders stuck into the dynamic elements of the chrome, and the error message in the normal content area, but in the application's normal error style.
If your side bar had a list of "Recent Posts" or "Upcoming Events"; the type of thing that would like like 3-6 links and then have a "[more]" link, how would you degrade that gracefully? (I know about createing a "Null Object" to fake being the database, but what would you suggest showing? Something like "Data temporarily offline" or "Technical Difficulties" or "[none]", etc)
I try to work the design such that the information hides, just not showing anything. Certain things, like say a calendar, would in itself still display, but a small note would be placed underneath stating the information source is unavailable at this time.