QUOTE
Force Quit all that haven't been used for several days
Why the 'heavy hand' technique? Hold the command key down ( and keep it down untill I say to release it ) and press the tab key. There's your running apps list as larger icons. Each press of the tab key will select the next icon to the right ( shift-tab goes the other way ). When you find an app you want to quit "q" key. It will quit ( remember, command-q is the Mac standard way of quiting any app ). When all unrequired apps have been quit, tab to the app you want to use again, if not already selected, and let go of the command key. You're done, no mouse required, no window left open, no electrons have been harmed.