Curtain rod brackets should be placed at the appropriate height and distance from the window frame. The general rule of thumb is to position them about 2-4 inches above the top of the window frame, allowing enough space for the curtains to hang freely without obstructing the view when open. Additionally, the brackets should be placed evenly on both sides of the window, ensuring stability and balance. It is crucial to use a level and measure carefully when installing curtain rod brackets to ensure that they are straight and symmetrical.