Omit unnecessary words. Develop one idea per paragraph. Start with a simple topic sentence containing that idea. Follow with details, examples and definitions. Few get it right the first time.
Good writing means rewriting.
Lively writing contains action verbs, not passive ones. That's not always possible, especially when you're talking about ideas. Or you might take a lesson from the safety announcements given by airline flight crews prior to takeoff. They are masterpieces of ambiguity - and deliberately designed that way, of course. They don't mention just why you might need to be floating or the frightening necessity of determining how long you can tread water.