As a writer who often covers "evergreen" subjects, I'm constantly looking for new, "fresh" ways to pitch a story. (And believe me, editors want the same thing!) Instead of pitching "10 ways to lose weight," for example (boring!), I might instead pitch a piece on the surprising reasons you're gaining weight; how lack of sleep can make you fat; how your friends and family may be making you fat; or how even your environment cause you to gain weight. Get the idea? You scout for different ways to approach the same basic idea.
I've found that one of the most effective ways to do so, and to up my chances of getting an assignment, is to employ what I call a "time peg." A time peg makes your evergreen topic of interest right now. Here's an example:
Dear Ms. Editor:
You've been watching your diet and working out, but that number on the scale just won't budge. Wondering what the problem is? The culprit may not lie with what you do during the day, but what you do (or don't do) during the night--namely sleep. A recently published study found that people who slept just four hours (compared to eight hours) a night consumed an extra 559 calories the next day! It's easy to see that several weeks of sleep could easily show up not just as undereye bags, but as extra around your middle as well.
[Rest of the query omitted.]Get the idea? The study gives my evergreen idea (how to change your lifestyle to lose weight) a timely spin, and makes it more likely to be assigned by an editor.
That's why I suggest you look for a time peg (be it a new study, a statistic, a news story, an anniversary of an event) to make your evergreen story timely. Are you doing this already? How do you make your evergreen stories sound fresh?