I know you review. I probably know how you review.
You search market guides for age levels, rights acquired, submissions guidelines and response times. You analyze stories and books for character, plot, and POV. You study hooks, transitions, structure and dialog. You examine articles for focus, presentation, tone, and style. You review to determine what editors select for publication and to scrutinize actual published products.
Of course you do. You're a writer.
As long as you're reviewing anyway, why not also review for ideas. Be honest. Wasn't that article on rainbows and refracted light for middle graders way too dry? Wouldn't rainbows be much more fun with a garden hose and a bubble wand demonstration for curious kindergarteners? At least, that's how you would have done it. Now there's an idea.
The market guide for magazine XYZ states they accept fantasy, science fiction, mystery and adventure. You pull out your sample copy and review a story called "Prison Planet of Zinn". The story piques your interest and sends you to What If? Land. Your own characters and settings roil through your mind, different of course, and still vague. Go ahead. Put down that magazine and pick up your journal. What If? Land is a writer's best friend. Indulge.
And don't forget those how-to-write books. Another writer's revelations regarding their habits (good or bad), methods (mad or sane), and sources of ideas (tortured or inspired) always motivate me. From Strunk and White to Barbara Seuling. So review the how-to's and the thou-shalt-not's and get psyched.
Keep your writer's journal near as you review. Don't allow the tiniest glimmers of ideas, characters, plots, or article slants to slip away into oblivian. With a little practice, jotting notes to yourself as you scan or delve into your daily reading will become second nature and not even distract you. You'll be surprised how many ideas for writing opportunities will arise if you practive this, and how few ideas will slip away unnoticed.