We as not-so-professional engineers have a habit of not putting in the required capacitors at place. We generally ignore the safety, noise suppression capacitors in power supplies of all kinds. These don't lead to immediate failure or fault, but it hampers the life of the product. It also makes the device the unsteady and this directly hampers user experience, which is of critical importance.
Leaving that to the personal jurisdiction of my fellow engineers, I move on to tell about a good capacitor trick. There is nothing great about it, but it adds a lot of grace to the device.
It's as simple as : Attach a capacitor in parallel with any LED in the circuit which needs to blink. What does it do, you ask? Well rather than the immediate turn on and turn off, the LEDs turn on and off slow and smoothly. From zero intensity they slowly rise to full intensity turning on and similarly when turning off.
Try it in one of your upcoming projects and notice the grace it brings. Oh, by the by, adjust the capacitor value to suite your taste and blink speed requirement. The law is simple, more capacitance makes the LED take long time to turn on and off.
An example of a MacBook doing the same.