If you are mostly using only one resample image option when resizing images, then you can change the default option to the option you are using the most.
Not your average pixel effect tutorial, let me show you a nice little trick where you apply the normal square pixelated effect and turn it into checkered, diamond looking photo pixels.
We will open a random photo taken at day light and add exploding fireworks to it. We will also we will modify the whole picture to make it as realistic as possible, enjoy!
