Blending modes are an integral part of both design and color correction workflows as they let you mix the content of two or more layers. Part of the reason many pass on blending modes is that they are hard to use if you don’t know which one you want. The truth is that the list can get a little long and if you aren't familiar with them, it can get a little confusing.
Here’s a much better way to experiment when using Adobe Photoshop or After Effects:
1. Select the layer or layers you want to blend.
2. If using Photoshop, choose the Move tool (In After Effects, you can skip this step).
3. Press Shift + = (Shift plus Equal) to scroll through the list.
4. To move backward, press Shift + – (Shift plus Minus) to return to a passed blending mode.
Be sure to check out my two Photoshop books – Photoshop for Video and Understanding Adobe Photoshop CS5.