A study carried out by Cranfield School of Management on behalf of The Chartered Institute of Marketing in the UK has led the author to formulate twelve guidelines for developing effective marketing strategies. These guidelines are discussed and are: understanding the sources of competitive advantage; understanding differentiation; understanding the environment; understanding competitors; understanding strengths and weaknesses; understanding market segmentation; understanding the dynamics of product/market evolution; understanding a portfolio of products and markets; setting clear strategic priorities and sticking to them; understanding customer orientation; being professional; and giving leadership.