What I do on new installations is:
cd /etc/fonts/conf.d &&
sudo rm --verbose 01-trisquel.conf &&
sudo rm --verbose 59-ttf-droid-serif-fonts.conf &&
sudo rm --verbose 10-hinting-slight.conf &&
sudo ln --symbolic ../conf.avail/10-hinting-full.conf &&
sudo ln --symbolic ../conf.avail/10-sub-pixel-rgb.conf
cd $HOME
gsettings set org.gnome.settings-daemon.plugins.xsettings antialiasing 'rgba'
gsettings set org.gnome.settings-daemon.plugins.xsettings rgba-order 'rgb'
gsettings set org.gnome.settings-daemon.plugins.xsettings hinting 'full'
gsettings set org.gnome.desktop.interface font-name 'Sans 9'
gsettings set org.gnome.desktop.interface document-font-name 'Serif 9'
gsettings set org.gnome.desktop.interface monospace-font-name 'Monospace 9'
Some of the lines might be wrapped.
The first block removes fonts set as default by Trisquel. This in turn sets
the default fonts to DejaVu, which are much more readable. It also sets the
system fonts to full hinting and sub-pixeled, which makes them crisp and even
more readable.
The other two blocks must be set for each user.
The first of the two set full hinting and sub-pixeled, again. I remember that
some programs, such as Abrowser, do not use these settings and others do, so
that's why it's needed to set them in both places.
The last block sets desktop fonts to the default generic ones. The generic
ones are equal to DejaVu, because of the first block.
