Buttons, electrically at least, aren’t things that I normally give much thought to. They either turn on or off. On the other hand, if you have a situation with a momentary pushbutton where whatever you’re controlling doesn’t give you instant feedback, you may question whether or not you actually triggered the device.
On-button feedback isn’t something I’d considered as a possibility, but after reading Owl Lab’s description of this Simple Button Switch Module, some sort of button press indication would be very important in many situations. Their particular module includes two LED diodes, one which indicates power from a 5 V supply, and the other which turns off when the switch is depressed, signalling low or ground to your microcontroller (switch is normally closed). It’s set up in such a way that you can know for sure that you actuated the button, and given its particular configuration, you don’t have to wonder if the LED is actually working.
On the other hand, if you have a situation where your button can potentially register multiple clicks via a single press, check out this post for a button debounce solution. Combined those concepts with this indicator for the ultimate in button stability!