 Begin by adding a new layer. (Ctrl+Shift+N) Call it “sunset”.  Click on the background color swatch and choose a bright yellow from the Color Picker.  Click the foreground swatch and choose a bright orange/red.

 Choose the Gradient Tool and select Foreground to Background.  Select Linear Gradient from Options bar.  Click and drag with the tool from the very top of the image, releasing the mouse button of the horizon line.  Set layer to linear burn, reduce opacity to 80%.

 Duplicate the original background layer. (Ctrl+J)  Go to Image>Adjustments>Photo Filer.  From the Photo Filter dialog box, choose Magenta from the Filter drop-down menu and increase the Density slider to 84%.

 Now we need to add the sun.  Click the sunset layer and select the Elliptical Marquee tool from the toolbar.  Select Fixed Aspect Ratio from the Style box in the options bar.  Create a new layer and call it “sun” and drag a small circle, overlapping the horizon. SUN!

 Choose a very light yellow for the foreground color and fill the sun using the Paint Bucket.  Ctrl+D to deselect the sun.  Blur the sun with Filter>Blur>Guassian Blur, using a radius of 5.8.  Set the blending mode for this layer to Vivid Light and reduce the opacity to 85%

 Remain on the sun layer and choose the Brush tool from the Toolbar.  Select a soft-edge brush from the Brush Picker, reduce the Brush Opacity to 33% and click on the Airbrush symbol in the Options bar.  Now paint with the bright yellow above the sun and between the clouds.

 Add a lens flare-Create new layer, fill this layer with black using Edit>Fill>Contents Use:Black.  Now go to Filter>Render>Lens Flare. Once the dialog box opens, choose Zoom at a brightness of 77%.  Drag the crosshair for the lens flare up toward the top right. Hit OK.  To hide the black, set the blending mode to Screen. Reduce the Opacity to 79% and move the flare into position.  Position the brightest flare directly over the sun.