Do you want to take screenshots on a Mac, but without shadow around the window? Then you can disable this by using a terminal command. Since macOS Mojave you have to use a different command than under macOS High Sierra (more info).
Mojave Dark Mode includes a new full Dark Mode. If this modes is to black for you, there is a possibility to reverse to the macOS High Sierra dark mode. The following procedure disables the full Mojave dark mode and only enables a dark menubar and dock just like macOS High Sierra.
Nothing is more annoying that Photos will opens automatically when you connect an iPhone, iPad or other devices to your Mac. Use the following command in Terminal to change this and prevent Photos from opening automatically.