How to quit your job to start something new, according to real people who left Facebook, Google, and Apple

Quitting your job and moving onto something new is always a nerve-racking process.

But just think about how people who've left the biggest companies out there must feel.

Business Insider has spoken to numerous alumni of some of the most talked about companies.

Many of them described leaving to tackle new ventures and chart their own course in the business world.

Here's some advice from people who've quit jobs at companies like Google, Apple, and Facebook on how to seize control of your career: