Microchip presents several of techniques for lowering the power consumption of their PIC microcontrollers and dsPIC digital signal processors. Many things can apply to any low-power project. [via]
This document seeks to simplify the transition to low-power applications by providing a single location for the foundations of low-power design for embedded systems. The examples discussed in this document will focus on power consumption from the viewpoint of the microcontroller (MCU). As the brain of the application, the MCU typically consumes the most power and has the most control over the system power consumption.
App note: Lowering power consumption on PIC microcontrollers - [Link]