Elon Musk and Richard Branson provide advice to entrepreneurs on starting companies. Some key points they discuss include focusing intensely on just one company at first, finding someone to run day-to-day operations so the founder can focus on bigger picture goals, expecting difficulties in the first few years as issues arise, and surrounding oneself with a team that shares the same mission and goals for the company. They also emphasize the importance of Silicon Valley for tech startups due to its infrastructure and network effects.