When faced with the task of taking part of one photo and blending it with another photo, you may run into the problem of color variances that make it obvious that one of the photos doesn’t “belong.” 
For instance, I want to take a photo of a building which was photographed in mid-day and drop it into a sunset photo. Obviously the photo of the building will look out of place due to the time of day the photos were taken. See the image above for what I mean, the building looks out of place. Fortunately, there’s an easy solution. 
Step 1: Open both your images in Photoshop and make sure both are in RGB color format (CMYK won’t work). Make sure that the image you wish to alter is selected and in front. In this case, I want to alter the building photo to look like it was taken at the same time as the sunset photo, so the building image is in front. See the image above. Step 2: Visit the menu bar and select Image>Adjustments>Match Color… The Match Color dialog box will open and you will be presented with several options. The first thing you want to do is go down to the Image Statistics section and select the Source image from the drop-down menu, in this case it is the sunset.jpg. This can be confusing because the preview shows the image you’re working on, not the source image. See the image below. 
Step 3: You will notice that your working image is now using the colors and tones from the source image. Now you can play with the Image Options in the upper part of the Match Color dialog box. See the image above. Move the Fade slider around to adjust the tone of the colors, and adjust the Color Intensity as well. Once you’re happy with the adjustments, hit OK. As you can see in the image below, the building image is looking better already. 
Step 4: Now simply copy the portion of the image you wish to place into the source image. In this case, I created a selection of the building before hand, so I’m just selecting the building, copy and pasting it into the photo of the sunset. 
Step 5: You may have to cleanup some of the rough edges of your selection, but that’s it. As you can see in the image above, the building looks more at home in the sunset photo than it did in the first image of this tutorial.
Category: Photoshop
Toggling tools in Photoshop with the keyboard
Keyboard shortcuts is one of the ways you can save a lot of time when working in Photoshop, it’s also a way for me to judge the knowledge of a prospective production artist. Learning them can make all the difference. 
Here are some frequently used keyboard shortcuts to toggle various tools in Photoshop. There are more, but these are the ones I use the most: “B” for Brush “C” for Crop tool “E” for Eraser “I” for Eyedropper “J” for Healing Brush tool “K” for Paint Bucket “L” for Lasso tool “M” for Marquee Selection tool “N” for the Notes tool “O” for the Burn/Dodge/Sponge tool “P” for the Pen tool “R” for Blur/Smudge tool “S” for Clone Stamp tool “T” for Type tool “U” for Shape & Line tool “V” for Move tool “W” for Magic Wand tool “Y” for History Brush tool
Get more accurate results with the Photoshop Eyedropper tool
If you work in Photoshop, you’ve probably used the Eyedropper tool at one point or another. Most users simply select the eyedropper tool and click on an area in the image to grab the color they want and that’s the end of it. But did you know there’s a more accurate way to select the color you want? When you use the Eyedropper tool, the default is to select one single pixel as a basis for the color you want to choose. So let’s say you want to choose the orange colored background in the photo above. If you use the eyedropper tool at it’s default, you might end up with a color you weren’t counting on due to the fact that there are many colored pixels that make up that orange, such as tan and brown, and the tool will only choose the one color that the curser is directly over. 
To get a better representation of the color you want, select the Eyedropper tool and go up to the toolbar and you will see “Sample Size” with a drop-down menu. Click the menu and select 3 by 3 average. This will look at a 3 pixel by 3 pixel area and average the colors to give you your selection, which is much more accurate and probably more closely represents the color you’re looking for.
Photoshop sharpening tips for designers
Virtually every image you bring into Adobe Photoshop—whether it be a stock image or from a scanner or digital camera—will need at least a little bit of sharpening. This is just something we, as designers, have to deal with in the digital age. Many photographers will balk at such a statement: if they’re good and take pride in their work, the photo is close to perfect in their eyes to begin with. However, once the photo is brought in to your Mac and your image manipulation is complete, a loss in sharpness is almost always present, no matter how perfect the original photo, negative or slide was. A recently published article at Macworld.com titled Photoshop Sharpening Tips for Designers offers some tips for sharpening your images.
Get better .eps preview images from Photoshop
You may have noticed that if you save .eps images from Photoshop, when you place them in InDesign, Quark or other layout application, the image is jaggy to outright ugly. This is because the .eps image is using the default preview mode of 1 bit/pixel (or 256 colors). 
You can get beautiful full color/full resolution preview images in your .eps file simply by changing the Preview setting when you save the .eps image. Simply select Macintosh (JPEG) from the Preview: drop down menu. No more jaggies! Never use the TIFF preview image option. It seems to cause a lot of problems with RIPs at service bureaus, printers and publications when outputting.
Go old-school bitmap with HyperDither
In the Mac’s early days, bitmap graphics were a big deal. Apple’s Bill Atkinson developed a fantastic dithering filter which converted grayscale images to 1-bit, black-and-white bitmap images that could be displayed on the Mac’s screen. To some observers, the Atkinson filter is thought to be better than the modern Floyd-Steinberg model (also known as the error-diffusion filter) used by Adobe Photoshop today. Read Go old-school bitmap with HyperDither for an OSX solution to getting the grand-ole-dither back.
Easily add vignettes to your Photoshop images
It’s a really old technique, and looks great when done properly. But adding Vignettes for some is overly complex. One of the easiest methods I’ve come across is this tip at LifeClever. 
But I’m lazy, so I’ll go even further into the “easy” method. With Photoshop CS2, Adobe added a nifty little filter that does, among other things, vignettes. Here’s how it works: Make sure your image is in RGB mode. Select Filter>Distort>Lens Correction… There are several sections of this filter, but we’re going to use (obviously) the Vignette portion. First thing you may want to do is turn off the grid with the checkbox at the bottom of the dialog window. Slide the Amount slider under Vignette toward darken. This adds darkness around the edges and corners of your image. Now you adjust the amount of vignetting with the Midpoint slider. Move it to the right to have less of the image darkened or to the left to have more of the image darkened. That’s it. You can also apply the same technique to a layer filled with white above your image and set the layer effect to Multiply – this will allow you to adjust the darkness later if you wish.
Adding realistic fog to your images using Photoshop
Get more bang for your buck by depositing a fog bank into your landscape photos using the Dissolve brush mode and the Gradient tool to vary density. Fog is actually transparent unless you try to look through layers and layers of it. Then it becomes dense, and in some places, impenetrable.
The secret to realistic fog is to vary its density…
David Diotaveli offers a pretty decent tutorial on how to add realistic fog to your images.
Hide multiple Photoshop layers quickly with this shortcut
Many times when you’re working on a Photoshop document that has many layers, you want to see just one layer at a time. It’s a pain to turn off all the other layers, especially if you don’t use Layer Groups. You can quickly turn off all but the one layer you want by holding down the Option key and clicking on the eyeball next to the layer you want to see – all the other layers will automatically hide. To get all your layers turned back on, simply repeat the process.
Get better details when sharpening your image in Photoshop
To get sharpening on steroids, try using Filter>Other>High Pass on a copy of the layer that you want to sharpen. Make the layer’s Blend Mode Overlay, Soft Light, or Hard light. Try using smaller High Pass settings to emphasize small details in the image.