1. Use PowerPoint in Your Practice!
PowerPoint offers a lot of power in a well-though-out and easy-to-use package. If you have never used PowerPoint, you can probably figure out how to create a decent basic presentation in a few hours. After that, it only gets easier. There are programs that do presentations better and that have more bells and whistles, but the fact remains that PowerPoint has grown into the position of the standard that most people use.
This is the clean slate you start with in Microsoft PowerPoint.
PowerPoint exists on both the Mac and Windows, and the files are effectively interchangeable. If you have Keynote and like it, by all means use it; but if you are working with others and sharing files or using the files in court, you are better off with PowerPoint.