ADJECTIVES AND ADVERBS, PUNCTUATION OF

a. Comma: Use a comma when two or more modifiers before a noun can trade positions with relative ease or when you can easily insert and between the adjectives:
the cheerful, busy children
the busy, cheerful children
When one of the modifiers explains, amplifies, or partly contradicts an earlier modifier, use commas: my samloh, or pedicab, operator. Do not put a comma after the final modifier simply because it has a modifier itself: men of that dim, often frigid past.

b. No punctuation: Use no punctuation when two or more modifiers before a noun are fixed in their relative positions and all modify the noun directly: traditional political institutions; a severe tropical storm. When in doubt, omit the comma.

c. Hyphen: Use a hyphen when two or more modifiers link to form a single concept that precedes a noun. If one of the modifiers is itself a compound, an en dash may be used instead of a hyphen.
a calf-size dog
a two-for-one bargain
iron-and-steel mill
a two-act comedy
iron- and steelworks
Civil War-era houses
low- to high-income housing
forest- and bush-loving antelope
nuclear-armed and nuclear-powered ships but not nuclear-armed and -powered ships

Punctuation can influence the meaning:

            red, white, and blue flags (solid-colored flags), red-white-and-blue flags (tricolors)

To avoid ambiguity, note:

            light-blue suit (color), light blue suit (weight)

Do not hyphenate compound color modifiers unless hyphenated in M-W or both elements are colors of equal value:

            blue-black sky, gray-green eyes, but bluish black sky, lemon yellow dress, jade green lake, cobalt blue dish

Do not hyphenate:

a. a compound modifier before a noun when the compound itself carries a modifier or after a noun unless subject to misreading or hyphenated in M-W as an adjective:

a well-built house
 a house well built
 a very well built house
 the house was well built

b. a compound proper noun used as an adjective. Hyphenate, however, a prefix before a capital letter, or when hyphenated in M-W:

New York skyline, but New York-born man or New York–born man (en dash)
 South American countries
 Latin American ways
 Old English customs
 pre-Columbian vase
 un-Burgundian ways

c. foreign terms:

bona fide friends, a de facto peace, per capita income, status quo policy, but laissez-faire policy

d. chemical terms used as compound adjectives except if ambiguous or when used with the mass number:

carbon dioxide test, but carbon-14 dating; iron-oxide red; strontium-90, strontium-90 fallout

e. widely used compound nouns appearing in M-W when they are used as adjectives, such as bald eagle, foreign exchange, income tax, and real estate, except where misreading could result and a hyphen helps readability

f. a two-word modifier when the second word is a possessive:

history teacher's papers, a planning council's decision

g. ordinals with comparatives or superlatives: second largest producer, third longest tunnel, first ever study, but first-grade potatoes, second-class citizens

h. compound modifiers with comparatives or superlatives unless subject to misreading:

more favorable weather, earliest known city, lesser known novel, best loved story
 but    best-selling novels, worst-case scenario

3. Adverbs that end in -ly are not hyphenated: 

faintly heard call

There are a number of adverbs that look like adjectives because they do not end in -ly. Of these, compounds with dead, long, near, and well are generally hyphenated before a noun:

dead-tired feet, long-established use, near-realized hopes, well-dressed man

A three-word modifier, the first of which is an adverb ending in -ly, need not be hyphenated unless ambiguity results:

freshly laid out linen, newly set aside parklands


See even. Consult M-W, especially for compounds with over and under.