The Magic Wand Tool allows you to select areas with consistent colors without tracing the outside of the area. Rather, you can control the amount of color variance allowed in the selection by adjusting the Tolerance of the Magic Wand. This, along with other options is available in the Magic Wand menu bar. Here are the options in order as they appear in the menu.
This image shows the Magic Wand being used to select the blue jersey.
There are four options for the type of selection you can choose. The default option is New Selection. This allows you to select a new area with the Magic Wand. If you need to deselect a portion of the selected area, choose Subtract from Selection and draw around the area you want deselected. Likewise, Add to Selection increases the selected area. You can also add to your selection by pressing shift while selecting regardless of which option you have active. Intersect with Selection allows you to draw two areas and the overlapping portion will be the selection area. You can continue to draw as many overlapping shapes as you would like until you have the correct area selected.
The next option is Tolerance. This adjusts the color variance that will be added to the selection when clicking on an area. A lower value selects colors more similar in color to the pixels clicked on; a higher number allows a broader range of colors. Anti-alias smoothes the edges of the selection. If selected, contiguous only allows the Magic Wand to select similar colors that are touching the area selected. If not selected, similar colors in the Tolerance range will be selected anywhere in the image. Sample All Layers allows you to select from all layers rather than just the currently selected layer.
For more control over the edge of your selection, click on the Refine Edge button. The Refine Edge button allows you to refine your selection and view your selection against a neutral background so you can more clearly see how your selection will look. Select a portion of your image, and then click on this button. By default when you choose this, everything outside of your selection will appear white so you can more clearly see what you have selected. You can then use the sliders to adjust the selection area. Make sure Preview is checked so you can see the results of your changes.
Radius controls the size of the area inside the selection boundary where the edge refinement occurs. The higher the number the more contracted from the original selection area. Contrast sharpens the edges of the selection. The higher the Contrast number the more defined the edges will be. Smooth controls irregularities in the selection boundary. The higher the number, the more smoothed out the selection boundary will be. Feathering the selection will create a faded transition from the selected area to the area outside the selection. The higher the number, the larger the feathered area up to 250 pixels. Contract/Expand enlarges or minimizes the selection boundary. Positive numbers expand and negative numbers contract. This tool in conjunction with others can help fix problems in your selection boundary. For example, if some of the background is still visible around the edge of your selection, contract the boundary. Below the sliders are five options that allow you to adjust how your selection is previewed with descriptions below that describe each option.