Tip 2: Vary your Opacity
(Click for a full-res image)
When you make a major change, it’s good to do so on a duplicate layer. Then, if you need to, you can reduce the effect by decreasing a layer’s opacity. This works on Adjustment Layers, too. Here, I duplicated the Background Layer, renamed it Vignette, and added a slight vignette. But it was still too much. To turn it down, click on the small pulldown menu next to Opacity, and move the slider until you like the way it looks.