The Clone Stamp tool has been the tool of choice for removing distracting or other unwanted objects in photos for years now. Although the Healing Brush in many ways offers a better and more realistic alternative, there are certain situations where the Clone Stamp tool is still the best tool for the job. Here's an example of how this workhorse removes unwanted objects:
Nothing ruins old-world charm like a screen-printed sign for a restaurant and a utility light from Home Depot. The stain on the street in front of the door doesn't kill the old-world charm that much, but it's distracting, and since we're going to remove the sign and the light (the three offending objects are circled here), we may as well fix the street at the same time, eh? Let's do it.
Press S to get the Clone Stamp tool. In the Options Bar, click on the Brush thumbnail to the left of the Size pop-up menu and choose a medium, soft-edged brush in the Picker. Now, hold the Alt key and click once in an area of wall just to the left of the light. This is called "sampling." You just sampled a wall area, and in the next step, you're going to clone that wall area over the light to completely cover it. (By the way, when you sample, a little "target" cursor appears letting you know you're sampling.)
Move directly to your right and begin painting with the Clone Stamp tool. As you paint over the light, the wall you sampled is cloned right over it, so it looks like the light has disappeared. Paint a little in this area to get a feel for how the Clone Stamp works (at least, if it's your first time cloning; if it's not, then you know what to dostart cloning over that light). As you can see here, that light is now gone! The key technique to remember is to sample in an area where the basic light and texture are the same (to the left of the wall), then move straight over to the object. Note: The little plus-sign cursor (the area where you sampled) is just to the immediate left of the target cursor (where you're painting now). By keeping them side-by-side, you're making sure you don't pick up patterns or colors from other parts of the photo that would make your cloning look obvious.
Now, we're going to clone over the sign, and to do that, start by Alt-clicking in an area that has similar tone and texture as the sign. In the example shown here, I Alt-clicked on the right side of the door (near where the light used to be) because both sides of the wall have a similar texture. Normally, you'd Alt-click next to the sign, but in this case, you can get away with Alt-clicking farther away.
Look at the plus-sign cursor (on the right side of the door). That's where I sampled, and now you can start painting over the sign to clone over it (as shown on the left), but it's important to understand why you have to sample from an area that has similar color and texture. For example, try this: Alt-click on the bottom-right side of the door (near the ground), then go up and start cloning over the sign. Look how much lighter (and obvious) the cloning looks (as shown on the right). That's why you usually have to sample very close to where you clone. If not, it's a dead giveaway.
One of the tricks to removing objects realistically is to sample often (by Alt-clicking) in different but nearby areas so that your cloning appears random, therefore avoiding repeating patterns.
In the example shown here, I've chosen a different spot and Alt-clicked. Then, I started cloning away more of the sign. During the process of removing something as large as the sign, you may want to Alt-click in slightly different areas three or four times, so your cloning looks natural and random. Just keep in mind that wherever you Alt-click, make sure the tone and texture are the same as the area you're cloning into (in other words, it should look the same as the area that currently surrounds the sign).
Alt-click the Clone Stamp tool in the street to the right of the stains, then paint right over the stains in the street. The clean area of the street that you sampled will hide the stains in the street, completing the technique.