Don't hyphenate; ongoing is one word.
"One of a kind" has hyphens between each pair of words when it precedes whatever it is modifying: for example, in "Each lamp is a one-of-a-kind work of art." However, if it is used as a predicate adjective, it is not hyphenated: for example, "This sculpture is one of a kind."
You do not hyphenate one by one. See, for example, the use of those words in the definition of "count" in the Random House Webster's Unabridged Dictionary.
You do not generally hyphenate the word stepchild, because it is not a hyphenated word. If the question is where to hyphenate stepchild if you have to break it across two lines, it is not difficult to determine this, because the two syllables are actually separate words: step and child. If you have to hyphenate the word to break it, you would put step- on one line and child on the next. If the word is all on one line, you do not hyphenate it.
Hyphenate! One-eyed is how to tackle this one!
You do not. It is a single word, not a hyphenated one.
You do not need to hyphenate.
You do not hyphenate the number.
You hyphenate it only at the hyphen.
You don't hyphenate the words 'thank you'
I think it's more accepted to hyphenate it.
There is no need to hyphenate this expression.