Want to instantly make your writing look more professional? The secret can be found in Bryan Garner's A Dictionary of Modern American Usage in an entry titled "phrasal adjectives"--
When a phrase functions as an adjective--an increasingly frequent phenomenon in late-20th-century English--the phrase should ordinarily be hyphenated. Most professional writers know this; most nonprofessionals don't.
The primary reason for hyphens is that they prevent miscues and make reading easier and faster. Following are some examples culled from The Wall Street Journal and The New York Times:
There's more in Garner's book, but this snippet gives you all you need to know. You can find more examples in almost any print publication. By following the phrasal-adjective rule in your own writing, you'll immediately give it a more professional, polished appearance.
Publication Note: Originally published on 11/21/95, but just as true today . . .