In The Art of Branding, Guy Kawasaki shares some insightful suggestions. I liked this one:
Apply the opposite test. How many times have you read a product description like this? “Our software is scalable, secure, easy-to-use, and fast?” Companies use these adjectives as if no other company claims its product is scalable, secure, easy-to-use, and fast. See if your competition uses the antonyms of the adjectives that you use to describe your product. If it doesn’t, your description is useless. For example, I’ve never seen a company say that its product was limited, full of leaks, hard-to-use, and slow.