Quick Transitions are a simple way to speed up the editing process. You probably already use the "\" key to open up Quick Transitions to set a dissolve. But do you know you can access nearly any transition you use from here?
When you open up Quick Transitions there are a few default options. These are a little different depending on the version of Media Composer you are running but they should include at least: Dissolve, Film Dissolve, Film Fade, Fade to Color, Fade from Color and Dip to Color.