A Best practice is a technique, method, process, activity, incentive or reward that is believed to be more effective at delivering a particular outcome than any other technique, method, process, etc. The idea is that with proper processes, checks, and testing, a desired outcome can be delivered with fewer problems and unforeseen complications. Best practices can also be defined as the most efficient (least amount of effort) and effective (best results) way of accomplishing a task, based on repeatable procedures that have proven themselves over time for large numbers of people.
Despite the need to improve on processes as times change and things evolve, best-practice is considered by some as a business buzzword used to describe the process of developing and following a standard way of doing things that multiple organizations can use for management, policy, and especially software systems. As the term has become more popular, some organizations have begun using the term "best practices" to refer to what are in fact merely 'rules', causing a linguistic drift in which a new term such as "good ideas" is needed to refer to what would previously have been called "best practices."
Teaching isn't just talking at a chalkboard. Project management isn't just going through the motions. Both take a considered approach in implementing the best tools of your trade.