An interesting thing happens when working to create a themed photograph, freedom becomes oppressive and restrictions offer the greatest opportunities to explore. This seems counterintuitive at first but makes more sense when considering direction. Imagine for a moment you stop to ask for directions to a certain restaurant and you receive the simple answer of "drive east." Vague at best but it would at least get you headed in the right direction. You again stop to ask for directions and although the answer you receive is still vague you are told which streets to take to get to the general vicinity of the restaurant. Neither answer is incorrect as, sooner or later, they would get you to your destination but with the open ended answer of "drive east" you'll spend more time worrying about actually getting to the restaurant then anything else. In contrast, if you had a more direct answer, such as how to get to the general vicinity, you'll be able to explore more around your destination without too much of a worry that you'll actually get there.
To wrangle in this metaphor, my 'restaurant' in this case was a Halloween themed photograph. This, of course, is very open ended and having a general idea of wanting 'something spooky' might have gotten me started in the right direction but it was still too broad to get me where I wanted. I knew there were a few aspects I wanted to incorporate into a photo such as using an 85mm focal length for a tight shot, including a skull or bones in a subtle manner, smoke, and using different blend modes in photoshop to better learn how to use them. To get back to our metaphor, these restrictions directed me to the general vicinity of what I wanted and I was able to play around with what I could get there without worry of not getting anything at all. In the end, I decided on the photograph below: