From a recent trip. And can someone tell me how to layer in PhotoShop? The deal where you darken/lighten areas.
Layering itself isnt actually a tool in photoshop, layers are a means to keep components seperate, therefore more easily editable....
If you want to lighten/darken areas, then you want to dodge or burn, respectively. I will NOT recommend you use the photoshop dodge/burn tools however, since they damage pixel information, ruin the original image, and dont work too well.
Instead, create a new layer above the photo, change that layers "blend mode" to either color burn or dodge, and then use the brush tool with a light opacity, (15%ish) to "paint" the areas you want to darken. If you screw up, you can just delete that layer.
Curves adjustment, levels, etc can also help you change the overall look of a photos darkness, contrast, color balance, etc... Theres tons of tutorials online, but the best thing is to just play around with it and have fun!