Photoshop » Color Image Overlay

Find a picture of a celebrity, flower, animal or whatever you want to overlay with a brightness. Open it up in photoshop (the size of the image doesn't matter). I will be using an image of Rachel Bilson in an upset pose.

Once it's opened, press Ctrl+J to create a new layer on your layer palette (go to Window » Layers to open the palette). Once you have two layers, go to Filter » Blur » Gaussian Blur » 5.0. This will completely blur your image.

On your layer palette, change Normal to Overlay. That will clear the image up and make it brighter.

Now go to Layers » New » Layer... then on your left menu, click the gradient tool (the default gradient is usually black and white, but you can use whatever) just drag your cursor over your image, then do the Normal to Overlay again for that layer.