The phrasal verb ‘set out’ has a number of meanings in social and professional situations. Firstly 'to set out' can mean to begin something or to start working in on something in order to achieve a specific result. If you 'set out' objects it means to put things where they can easily be seen or used by others.' Set out' can also mean to explain something in a clear, sequential or detailed way. So you can 'set out steps' or 'sent out instructions' for example. 

1. William wasn't happy with my decision, so I had to spend an hour with him this afternoon setting out the reasons behind it.
2. Even though the steps for solving the equation were set out for me, I still couldn't figure out how to solve it.

1. In the first section of his report, the CEO sets out his five-year plan for the company.
2. Sandra's proposal sounded interesting, so I asked her to set out the details of it in an email and send it to me.

You can use 'set out' to talk about starting or beginning a journey, especially a long one. 

1. I'm setting out for London tomorrow to see an old friend of mine.
2. We need to start the journey early if we want to arrive in time, so I suggest we set out around 6 am.

1. In my speech, I set out to to explain in an entertaining and informative way how our product works, and I think I managed to achieve that.
2. Our client needs to set out for the airport at around 5.30, would you mind booking a taxi for her?