sudo dpkg-reconfigure fontconfig-config

Select “Autohinter”, “Always” and “No” when prompted.
sudo dpkg-reconfigure fontconfig

Add the following to ~/.Xdefaults (create the file if it doesn’t exist):

Xft.antialias: true
Xft.hinting:   true
Xft.hintstyle: hintfull
Xft.rgba:      rgb
Xft.dpi: 96

Add this command to your startup commands:
xrdb -merge ~/.Xdefaults

Restart X.