The fact of migrating or developing new applications on Azure provides the opportunity to review architectures, refactor code and apply best practices that we may have missed. This is most current documentation available from the MS Patterns and Practices team:
Solution development fundamentals cover the cross-cutting aspects of solution development, such as security, caching, data access, validation, exception management, and so on. It also includes application architecture, development process, the software development life cycle (SDLC), and application life cycle guidance. You will find guidance and patterns that are generally applicable to solution development regardless of the specific architecture or scenario.