Simplicity is a philosophy

Two steps:
1. Identify the essetial.
2. Eliminate the rest.

Six principles:
1. Set limitations.
2. Choose the essential.
3. Simplify.
4. Focus.
5. Create habits.
6. Start small.

Multitasking or not?
Inevitable and learn to get used to it. Multitasking should be at project level, not at task level.

In addition, the author's blog, zenhabits.net, is great.