When I begin a new copywriting project, I might write 20 or 30 or more headlines. Some are simply multiple variations on a single theme. Others are wholly original and separate from the rest.
At the conclusion of my brainstorming, I will choose one headline to use in the letter. But I don't throw away all the B-level material. I save all of it. Here's why...
Make Great Subheads!
Often, I will come up with three or four compelling headline ideas. I hate to choose one and throw the rest away. So I will keep the "losers" and use them as subheads. This is a time saver... and it strengthens the copy.
I have also found that I will come up with great subheads while I'm writing headlines. I immediately identify these by writing "subhead" in parentheses next to the copy I intend to use as a subhead.
To sum up:
Never throw away "bad" headlines. They can still be profitably used as subheads.
Pay attention to subheads that may pop into your mind while brainstorming. Note them as such for easy reference.
If you do both of these things, it will take you less time to write and you will write stronger copy. Try it out and see for yourself how well these techniques work.