I tend to put a lot of little functions in my init.m file, functions that take arguments and use module variables. I found that I would now have Global symbols like x, var, date, name, etc, before even running any commands.

So the interesting thing I have in my init.m file is a package structure:

BeginPackage["Init`"]

<exported functions list>

Begin["`Private`"]
<implement functions>
End[]
EndPackage[]

never regretted it.