Instructions
Wear out a Rubik's Cube or purchase a second-hand cube. Worn-out cubes are looser, which means you can rotate them faster with less resistance.
Stretch before a race. Just as you would stretch your muscles before an athletic competition, you need to stretch out your fingers before a run on the Rubik's Cube.
Study the algorithms. There is no single fastest way to complete a Rubik's Cube --- it all depends on what you are most comfortable with. For example, some prefer to start by aligning the four corners of a side before completing that side, while others use techniques such as the White Cross or more advanced formulas.
Practice slowly until you become comfortable in your pattern. The trick to quick completion is not dumb luck; it is the ability to quickly implement your strategy. Practice it at increasingly fast speeds to build up your confidence and ability to work the cube without getting lost.