One of my last little annoyances about Mint with XFCE has been solved.
I like to use a single click to open files or activate icons. In most Linux distributions this function is enabled and disabled in the file manager, and because the primary file manager also controls the desktop, changing to single click to open files in the file manager, makes that available on the desktop.
But not in XFCE. So I was messing around planning to change the default icons that are displayed on the desktop.
I right clicked the desktop, chose the Desktop Settings Option, then Icons - and there it was staring at me.
 Single click to activate items.
So now I have one more little thing sorted out. Searching the net suggested that double clicking to open a folder or file on the desktop is just something we just have to learn to live with. but it is not - now I know where to find it.