THE SOLUTION
Start with the same techniques we discussed for deep depth-of-field storytelling images (see here). Pick a small aperture, such as f/22, set your focus to the near point of your range of focus (usually 3 feet or 6 feet), and then take a meter reading off of the sky, which is often much brighter than the landscape, to determine the appropriate shutter speed. With these exposure settings ready to go, compose your shot. Now it’s time to add your flash.
If you’re using your flash in manual mode, plug in the aperture on the back of the flash to get your flash-to-subject distance. If you’re in TTL, the flash will give you a distance range. Make sure your flash is set up the specified distance (or within the distance range) from the foreground subject you want to illuminate.
Depending on the color of the light falling on your background, you may want to add a colored gel to your flash to warm up the light. Just remember that a gel will cause a loss of light from the flash (an amber gel subtracts about 2/3 stop of light). To compensate for the reduced light, move the flash closer to the subject to maintain a correct flash exposure.