Blend modes can give some really cool effects, but it can be a pain to scroll through them, especially on a Mac. With a PC it’s easy. Just click in the Blend Mode box so the mode is highlighted and use the up and down arrow keys on your keyboard. But that doesn’t work on a Mac. So what do you do? With the layer active, select the Move tool and hold the shift key and press the + (plus) or – (minus) key to flip through the blend modes. And this works for PC too.