One problem (for me) with the Raspberry Pi, is that it doesn't have any Power/Reset buttons, making the shutdown or reset boring, because you have to write the reset command, select to reboot from inside the OS (or remove the power cord) in order to reset it or choose "shutdown", to shut it down. Here is a simple tutorial, to add these buttons easily.
In some cases, you may need a Reset switch, to avoid plug in a keyboard and type in the "Reboot" command or anything like that, so you can reboot your Raspberry Pi safely. To add a Reset switch is very easy.
A reset switch
Cables for connecting with Raspberry Pi, either by soldering on board, or by using a standard two-way, one-row male header.
Raspberry Pi has already the pins needed for resetting the system. In my case, on a Raspberry Pi 3, these pins are there:
I wanted to make a project with Raspberry Pi and make it shut down automatically, before the power turns off (in a car project for example, where you want to turn the key and close everything), as the Power up it doesn't matter, it will boot when you give it power.
In this image below, you can see how to connect your switch (image is from raspberry-pi-geek.com):