I haven't done a tutorial yet, but here are some further tips:
(This is not the "slickest" way of handling this, but this is just as fast and requires less explanation)
1) add the clip you're going to use in the drop zone to the storyline as a connected clip (anywhere - it doesn't matter).
2) any color corrections you need - do it before you apply to the drop zone
3) any trimming you need - do it before you apply it to the drop zone -- this is especially important if you need to drop zone to start playing from a specific location within your original clip and not from the first frame.
4) drag the clip under the storyline (you'll use it to "time" the PiP effect)
5) add the PiP HD Title to the storyline as a connected clip (usual application for a title)
6) click on the drop zone icon in the Title inspector and click on your edited clip (under the storyline) - then Apply
7) line up the dropzone clip (under the storyline) to the beginning of the PiP title (turn on snapping - it will be easier)
8) drag the end of the PiP Title to the length of the drop zone clip (or less)
(you can delete the edited dropzone clip from the project at this point to get it out of the way)
HTH
One last thing: if you run into a "weirdness" where the inspector is blank even when clips are selected, go out to the projects level, then back into your active project... I don't expect FCPX to crash... it's just an anomaly in its behavior that I ran into (for which I'll venture a guess that it's the drop zone in a Title...suggestion: don't double click on the drop zone in the canvas - this effect is not intended to be used with scaling and positioning inside the dropzone.) Once it was cleared up, it didn't happen again (with that instance of the PiP title). Let me know if you experience this issue. You might want to try it out in a practice project first.