An easy way to get xfce is with the Xubuntu distribution. I've run that since 14.04, or maybe longer. I get all the benefits of Ubuntu with a lot less UI churn.

If you already have an Ubuntu box, you can also install the `xfce` package or do this:

    sudo add-apt-repository ppa:xubuntu-dev/staging
    sudo apt update
    sudo apt install xubuntu-desktop