How do I avoid rookie mistakes when taking pictures?
I am a professor and I see rookie mistakes in student papers all the time. For example, using too many direct quotes, not double checking the reference section, or capitalizing variable names like they are a Big Deal. Seriously, if you wrote "I went to the Grocery Store to buy Carrots and Broccolli" on facebook, people would think that you grew up in Bosnia or a basement dungeon. (too soon?)
I'm getting started into some hobby photography and I'd like to know what "rookie mistakes" to avoid. Are there certain things that newbies tend to do often? Are there certain angles, shots, poses, etc that you want retired forever? What are your photographic pet peeves?