Regardless of your corporate colors, my suggestion for all your presentations is to use a simple blue background, white type, and no more than four or five bullet points per page. A small company ID logo in the lower or upper corner of each page can help brand it a bit. Keep graphs, charts and pictures simple and clean with very few words and numbers. If at any point in your presentation you have to apologize for a slide because it's too hard to read, dump the slide. This may sound harsh and generic, but it works.
Stories have a beginning, middle and end.
Most PowerPoint presentations wander aimlessly while trying to follow some logical progression. Creating an agenda for your presentation will help organize it. But start by describing who you are, tell people why and how you do what you do, and then end your presentation with a call to action or reasonable conclusion that wraps the entire package together and makes a point. Stick to the script, stay focused, and don't freelance. So often PowerPoint slides and what the speaker is saying seem to be from two different presentations.