On my windows PC, I could click a select box and then cycle through the options with my up and down arrows. For example, changing blending modes in Photoshop is easier and quicker when I have this capability. On OS X, when I click a select box it doesn't "stay" selected, so I have to keep using my mouse to go through the options. Is there a way to enable this? Or is this just a part of having a Mac that I'm going to have to get used to?
It's been a month but I found a solution to your problem. I actually forgot this thread and stumbled upon the solution by accident. I felt the need to return to this thread to answer you because of Consultant's rude response.
Select a layer, and then with a non-drawing tool (Meaning all tools except brush, fill, stamp, dodge/burn, etc.) hold Shift and press
- or
= to cycle through blending modes. Shift - moves up one blending mode and Shift = moves down one blending mode
There are quick hotkeys such as Shift+Option M for Multiply and Shift+Option N for Normal. Some of them are hard to remember, such as G for Lighten and L for Hard Mix.
Edit: for certain Adjustment Layers, you might have to use Shift+Option - or = instead of just Shift - or = because Shift - or = will edit the settings within the Adjustment Layer instead of cycling through the Blending Mode