For Mac users, here's a little tutorial on how to take selection-based screenshots. Think of these as computer screen 'clips.'
 Arrange your screen as desired. Then press Command + Control + Shift + 4. Use your mouse to click and select the area you want to clip.
 Open the program Preview
 Go to File > New from clipboard, or use the shortcut Command + N. This should now put your clip into a new file, which you can save.
 Go to File > Save as and place where desired.
Easy peasy lemon squeasy!