So one thing that used to trouble me with using Drush was that finding modules to enable could kind of be a chore. Especially when, lets say, you have a client who has over 200 modules on their site.
What I used to do was something like this:
$~: drush pml --package="notifications" --status="Enabled" --type="Module"
Now, that works pretty well - except when, for example, you may be looking for a module with notifications in the name that isnt part of the notifications package. We all know how complex this can get!
So, one day it dawned on me to use grep alongside drush! Duh! (grep is available in most *nix systems, and on windows with cygwin installed).
$~: drush pml --status="Enabled" | grep notifications
You may get more exacting results with this! :)