Photoshop has many different ways of blending layers. Different blending modes determine how the pixels on one layer effect the pixels on other layers beneath it.

The NORMAL blending method simply filters the pixels on one layer onto the other layers, shifting the pixels closer to the top layer’s color.

Different blending modes are available right under the LAYERS tab.

Color Dodge, depending on the opacity and lightness of the pixel, brightens and saturates the underlying pixels.

The NORMAL layer looks dull and de-saturated, while the COLOR DODGED layer whoops the monkey’s ass.

The above pictures both have layers with COLOR DODGE blending. Blurring the layer makes a nice gradient from brightness to the background pixels. Use this effect to give your imagery a sweet GLOWING effect.:)

i found out accidentaly this lil trick but i guess i must share this for some artists out there who works things finely when they got white background (or any color actually) istead of neutral grey.

click Paint Bucket Tool (G)

select a foreground color (i chose pink on the image above)

point your mouse to the Photoshop Working Area (the grey one)

While holding Shift key, fill in (by doing left click) the area surrounding your canvas workspace.