I find it tedious to create parameter files for my ARM templates. With the script I just wrote you don't have to.
Simply point at the ARM template that you need a parameter file for, and the function will spit out the json that matches. Pipe it to Out-File or "clip" to put it in your clipboard and paste it into Visual Studio or other ARM template editor of choice.
Go grab it here - remember to rate if you like it :D