I spent quite as few years as a contractor and I quickly discovered the best way to be effective was to learn how to be effective with everything in the default settings. At every new place I went I could just jump right in. No need for any time spent fiddling with settings or tweaking and installing pluggins.

Although a slight counterpoint is that I also used to have my git settings file stored in a github gist so I could just grab my latest one and every new environment would have the same set of aliases I was used to.