N1: Hyphens: Use a hyphen to connect compound nouns or compound adjectives that come before nouns. Do not use hyphens with compound adjectives that come after nouns. See Writing for Success Section 3.80 pp. 125-126 or the following: http://grammar.ccc.commnet.edu/grammar/marks/hyphen.htm
Use a hyphen to connect compound adjectives that come before nouns
They went to a well-traveled trail that was too crowded.
She ate a plant-based diet for the entire year.
Do not use a hyphen when the compound adjective comes after the noun.
The guidebook was right about the trail being well traveled.
Every item in her pantry was plant based.
Use a hyphen to connect compound nouns.
His comic book featured a beast known as the man-pig.
My father-in-law knows how to perform taxidermy.
Use a hyphen to connect numbers and fractions.
When Abraham turned fifty-five, he decided it was time to marry.
My DNA test showed that I’m one-eighth East Asian.
Use a hyphen to connect prefixes like self-, all-, and ex- to their root words.
Francis needed to build his self-esteem before he could wear those pants.
His ex-wife dangled the car keys in front of his face.
Mark never stopped his quest for the all-powerful coffee bean.