Nested queries or temp (#) tables in SQL Server
The SQLCat team ideas and articles are sometimes pitched at edge cases that most folk will never see given their load or database size.

Saying that, the ideas they give there are common techniques to improve performance (eg change OR to UNION)

Temp tables have some issues around stored procedure compilation etc, but don't confuse these with table variables (the SQLCat articles mentions this). Also, temp tables should be local not global to separate processes don't affect each other 

Personally, I use temp tables quite often to break queries down: but not all the time. If I can do it in one SQL statement that runs well enough (for it's frequency of use) then I'll use that.

In your case, I'd identify a few problem queries and see if using temp tables suits these better. If you can't see any problem queries then do nothing.