What works for this less-than-a-year user of Trisquel 7 is to run Software
Updater from the GUI whenever I feel like it, and then run sudo apt-get
update and sudo apt-get upgrade immediately thereafter, just to fill in the
blanks. It's entertaining to see whether Software Updater asks for
authentication (not when it's just a security update).
What we all could use is an "Are your sure ?" response from the console when
(absent mindedly) running sudo apt-get upgrade without first running sudo
apt-get update.
It helps not to become alarmed when sudo apt-get update says that a file is
not available, as we sometimes ask too soon while the repository itself is
getting updated. Wait a few minutes and try again.
These update/upgrade routines are awesomely reliable. Thanks to all who make
that possible.
