MuseScore -- Index -- Cross staff beaming

In piano scores it is common to use both staves (bass and treble clef) to write a musical phrase.
This can be entered in MuseScore as follows:
First enter all notes
in one staff:
Beamed notes in upper staff
Shift + Ctrl + Down moves the selected
note or chord to the next staff
Selected note moved to lower staff

See also Bar Line for cross-staff bar lines (i.e. grand staff).