Throw Away Your Code:

I have always found I tend to start writing code way too soon and so I continually find myself with lots of pieces of code in a file (code which might be functional but it is not connected to each other yet and therefore not compatible and thus useless). 

This always leads me to taking only a portion of this code, moving it to a new file/project and abandoning the old code to focus on a specific thing and build upon it as I am able to complete goals/design aspects. 

To some extent this is caused by poor planning and/or over enthusiasm and trying to write multiple parts of the code at once.