Personally, I like to have each type of meeting on my Outlook calendar display as a different color. I often am handling multiple projects, so I'll assign each project a color and use it to easily see what projects I might be meeting on any given day.
When I converted from 2007 to 2010, I lost my settings for this feature. Today I finally searched and found instructions to re-do my conditional formatting settings in Outlook Calendar. This is similar to using color categories on emails, however it is created and maintained using the "conditional format" setting.
See this article for detailed instructions: