I have to design a brochure for a client. I don't understand much of brand identity, but my client says his brochure should reflect the following:

1. Professional
2. It should not be the flavour of the month
3. Must inspire confidence
4. Must reflect the strength of the team
5. "Our corporate promise is: Reliable Energy". Therefore, it should inspire reliability.

My question is, while designing, what are the things that I need to keep in mind so that I adhere to what he have asked for? 

I understand that the design should be simple, with standard colour and fonts. Apart from that, how can I make the brochure reflect the list above? How do you translate this in terms of design?