The Sustainable Materials Management Coalition has issued Guidance for Life Cycle Thinking and Its Role in Environmental Decision Making with a good description of how life cycle thinking will help avoid mistakes made focusing too narrowly on the “solution” of the day (recycling, biodegradation, local, etc.). Life is a complicated set of systems that require thinking through potential impacts at each stage of the life of a product - from raw materials acquisition to manufacture to use and final disposal and the transportation in between each activity. The report offers several examples of counter-intuitive findings of life cycle assessments (LCAs). It also notes well the complications and shortcomings of formal LCAs. Fortunately, just taking some time to think through the several stages of the life cycle and how different alternatives compare can raise awareness of issues that may lead you to a different decision than you may have thought.
EPA's Mathy Stanislaus also supports life cycle thinking here.
Here's a short presentation of my Life Cycle Thinking Matrix tool: LC Thinking Matrix. See EHS Strategies, Inc. for more information