Using the Rectangle Tool, draw a rectangle 266 pixels wide by 300 pixels tall. Apply a Fractal Clouds fill using light yellow and orange (RGB values shown) and adjust the fill arrows as shown. Click on the fill with the right mouse button and change the resolution number on the Infobar to 90 and the Density to 2. Press Enter to apply the fill. Make a duplicate of this rectangle and modify the fill as shown on the right side of the illustration. Apply a Flat, Stained Glass transparency, amount 50%. When the two Fractal Cloud-filled rectangles are centered, the result will be a soft cloudy sunset sky.
Draw a new rectangle, 266 pixels wide by 366 pixels tall. Apply a solid RGB fill, red 102, green and blue 0. Place this rectangle on top (Ctrl-F) and center the rectangles with the two smaller rectangles aligned to the top. Apply a Linear Transparency, type Mix. Position the start and end of the transparency as shown, leaving a solid deep red portion at the bottom that fades out very quickly. This will add a soft winter haze to the sunset sky.
Finally, using the Ellipse Tool, create a circle 95 pixels in diameter. Apply a light yellow fill using the values for the light yellow fill in the upper left corner. Place a rectangle over the lower 1/5th of the circle and Combine Shapes -- Subtract Shapes (Arrange menu) to trim off the bottom of the circle. Position the circle on the bottom of the orange sunset sky-filled rectangle and apply a Linear Transparency, type Bleach.