Best practices for PRINCE2 are called, confusingly, Principles. There are seven PRINCE2 principles and you can see how they fit into the structure of PRINCE2 in this diagram.
The best practices (or principles) are given below.
Continued business justification. There should always be a business reason to start the project in the and this justification should continue throughout the project lifecycle.
Learn from experience. Because projects are transient, it is vital that they take advantages of lessons from previous experience. These lessons are therefore explicitly recorded and implemented during each the project. At project closure, any lessons learned are documented and stored for future projects.
Defined roles and responsibilities. Its is important that the right people are involved and know what is expected of them. This engages all stakeholders (business, user and supplier) within the project.
Manage by stages. Every project is planned, monitored and controlled on a stage by stage basis. These management stages provide senior management with control points, while having the high-level plan split down into detailed stage plans. A PRINCE2 project has at least two management stages: an initiation stage and a delivery stage. Larger projects may need to use as many stages as required.
Manage by exception. PRINCE2 sets tolerances at the directing, managing, and delivering levels. As long as forecasts are within these tolerances then each level can continue. The moment a tolerance is forecast to be exceeded, the details and options for recovery must be escalated to the next level for resolution via an exception report.
Focus on products. This enables an explicit understanding of the products/deliverables that need to be produced along with their quality criteria. Because of this focus a PRINCE2 project clearly defines the scope of a project and provides the basis for planning and estimation.
Tailor to suit the project environment. As has already been mentioned, PRINCE2 is tailored to suit the projects environment, size, complexity, importance, capability and risk. A major document within PRINCE2 is the Project Initiation Documentation or PID. Part of the PID specifies how the method is to be tailored for any project. In my experience most tailoring in practice is for small projects – see my posts on PRINCE2 for small projects (< 1 person month) and PRINCE2 for medium projects (1-2 person months).