I was leading an Excel Intro class the other day and one of the participants asked "how do I graph four variables in one graph? I was not ready for that question and puzzled over it. I responded that 2D graphs show two variables, 3D graphs show three variables but 3D graphs may look good for a marketing or show and sell presentation, not really for serious mundane comparisons. I suggested a bunch of 2D charts on worksheet acting as a canvas.
The participant wasn't satisfied and said that someone in the firm had "done it before" and so I said, "well show us an example and we can figure out how to make it so". To which the reply was "well, you're the Excel guru, I thought you of all people would know how to make one".
After a while, someone asked about Pivot Tables, what they were and yes, light bulb went on in my head and I showed them how to make a Pivot Table and a Pivot Chart as a quick example, with variable number of variables chosen at will and plotted on one or more charts.
I went home thinking - "How you do it doesn't come first, what comes first is your creativity in identifying what you want to communicate and then finding keystrokes / mouse actions is just simple".
Of course, this applies to Powerpoint Presentations as well. Here's a TED Talk which is just bang on target.