How do you achieve good power draw?
First of all, make sure you follow all of the advice concerning good draw shot technique. Also, many important principles involving power draw can be found in the physics-based advice section. More general advice and video demonstrations can be found in the elbow drop and pendulum stroke section.
Here’s a power-draw shot by Mike Masséy:
Here’s a video analysis of Corey Deuel’s famous power draw shot:
Here’s a good example of an elevated-cue power-draw shot.