If you ever get tired of holding down a key or a combination of keys to make your Mac observe any of several modes or behaviors at startup, you might be interested in preparing a few keysinkers. For example, you could use a couple of keysinkers to boot into Recovery Mode while you go fetch a cup of coffee. You can readily construct keysinkers using cheap fishing tackle (line sinkers) and Sugru or Oogoo.
Just adapt the bottom of the sinker to give it a flat surface and make it lean enough to accommodate the angle of your particular keyboard’s surface. I’ve been able to compromise the angle so that my keysinkers can remain stable for different degrees of keyboard tilt.