Focus on Being Productive instead of Busy

There are two synergestic approaches (or laws) for increasing productivity that are inversions to each other:

1. Pareto's Law (the 80-20 rule, the law of the vital few and the principle of factor sparsity)

Limit tasks to the important to shorten work time.
It is a common rule of thumb in business that 80% of your sales comes from 20% of your clients. Focus on this 20% who make up the majority of your profits and fire the 80% of your customers who take up the majority of your time.

2. Parkinson's law
Shorten work time to limit tasks to the important.
Identify the few critica tasks that contribute most to income and schedule them with very short and clear deadline.
Stick a post-it on the monitor and write "Am I being productive or just active?"
Focus on demonstrating results instead of showing dedication.
Identify 2 mission critical items for the day and get them done.
Limit the number of items in your to-do list and use impossibly short deadlines to force immediate action.

And please do not multitask, if you prioritize properly there is no need to multitask.