I might have written about this editing tip before, but I still saw so many mistakes with hyphens in Pitchwars submissions. Here's some advice on how you can comb your manuscript and fix this problem yourself.
A compound adjective is where you have two or more adjectives before a noun and the adjectives modify each other and not the noun. If you're not an English major (like me) that can make you dizzy. So lets do this with examples:
I have two cute dogs. The adjectives are two and cute. What are they talking about? The dogs. Can you switch them around? Not without sounding weird. So no comma and no hyphen between the adjectives. The sentence is correct.
I have a black haired dog. The adjectives are black and haired. What are they talking (modifying) about? Ah. Here's the trick. Black is talking about the hair, not the dog. THUS hyphen! The sentence would correctly be: I have a black-haired dog.
Can you get my little brown notebook? The adjectives are little and brown. They both modify the noun. Typically the rule with colors (like numbers) is not to use a comma between adjectives. This sentence is correct as is.
That is my tiny little dessert. Adjectives are tiny and little. You can switch them around and it still sounds right or is correct. You need a comma between them. That is my tiny, little dessert.
Everyone is crazy about a sharp dressed man. The adjectives are sharp and dressed. And yes sharp refers to dressed, not to the man being sharp. It needs a hyphen. Everyone is crazy about a sharp-dressed man.
He is a well known athlete. You're not saying he is a well athlete, so you need a hyphen here. He is a well-known athlete.
BUT change the sentence. That athlete is well known. And now you have a new ballgame. No hyphen.
Most of the time, you only hyphenate if the words are adjectives with a noun following.
There is ONE big, glaring exception (because there's always one):
DO NOT hyphenate 'ly words.
She is a highly motivated writer. This would stay the same. No hyphen.
That is a freakishly short girl. Again, no hyphen.
I like the smell of freshly mowed grass. No hyphen even though freshly modifies mowed.
So there's a short example of when to hyphen compound adjectives. (There are also certain words that are always hyphenated, but it's best you consult a list to find out what those are.)
Do you have any examples to share from your own writing?