After installation, the Desktop comes up with very tiny font size. To correct this, install the ATI Open Source Display Drivers. As the fonts are too small to read, either login from another machine via SSH, or establish an SSH tunnel on port 3389 and start an X-server on the remote machine. Then start the following command through SSH to bring up the settings window:

xfce4-settings-manager

Modify other xfce settings, such as auto-login, here: XFCE display manager.

Make sure the following line exists in /etc/apt/source.list:

deb http://http.debian.net/debian/ jessie main contrib non-free

Install:

# apt-get update
# apt-get install firmware-linux-nonfree libgl1-mesa-dri xserver-xorg-video-ati

Restart your system to load GPU device firmware.

Link: ATI Open Source Drivers

I have several sound cards available in my system: built in audio, a M-Audio 2496 sound card, and the sound driver for the HDMI output of the AMD HD3200 graphics card. To be able to choose input and output devices, you need to install PulseAudio Volume Control, which is not installed by default in xfce for Debian 8.1.

# apt-get install pavucontrol