The Magic Wand tool lets us select a consistently colored area (for example, a red flower) without having to trace its outline. We can specify the color range, or  for the Magic Wand tool's selection.We cannot use the Magic Wand tool on an image in Bitmap mode.

1. Select the Crop tool in the toolbox.
2. In the options bar at the top of the work area, make sure Width, Height, and Resolution contain no values. These settings constrain the dimensions of the crop rectangle. If necessary, click the Clear button to clear them.
3. Drag over the part of the photo that you want to keep. To straighten or rotate the photo, drag the cropping rectangle over the entire photo.
4. When you are satisfied with the size and location of the cropping rectangle, press Enter (Windows)

We can fill an area with a gradient by dragging in the image. The starting point (where the mouse is pressed) and ending point (where the mouse is released) affect the gradient appearance, depending on the Gradient tool used. 

There are five gradent options are available in Photoshop:
Linear gradient : to shade from the starting point to the ending point in a straight line.
Radial gradient : to shade from the starting point to the ending point in a circular pattern.
Angle gradient : to shade in a counterclockwise sweep around the starting point.
Reflected gradient : to shade using symmetric linear gradients on either side of the starting point.Diamond gradient : to shade from the starting point outward in a diamond pattern. The ending point defines one

We can load, edit, and create libraries of tool presets using the Tool Preset picker in the options bar, the Tool Presets palette, and the Preset Manager. We can also save and reuse tool settings using tool presets.

The Eye icon allows us to make layers visible or invisible within the image window. Click the eye icon within the pen layer. The eye icon disappears and the pen image becomes invisible. Click the Visibility toggle again. The Eye icon displays and the pen image appears one again on your image window.