Fixing awesome's mouse cursor
Getting awesome to use the GTK2 and cursor theme you want it to is a matter of simply creating a file named .gtkrc-2.0 in your home and setting the theme there.
gtk-theme-name="Your-Theme"
gtk-cursor-theme-name="Your-Cursor-Theme"
Setting the GTK3 theme is as simple, but the file is ~/.config/gtk-3.0/settings.ini.
Most GTK apps honor that setting. But X has a default cursor that is used for non-GTK apps. That, annoyingly, includes the desktop background. In order to get X to use the same cursor, you have to run one additional command:
sudo update-alternatives --config x-cursor-theme
That will present you with a list of cursor themes to choose from. Pick your favorite, restart your session and you're set.