Hi Dave
Maybe take a tip from Tim Fitzharris and put yourself in front of one of the larger cacti as a foreground element,giving your eye a leading feature to start your eye to roaming over the image to the beautiful middle ground and then on to the rare colorful sky and back around again to the front, completing the circuit. I sometimes like to use a wide angle 12mm and get within 2 or 3 feet from my foreground subject. Focus using the depth of field for that particular lens. Ex 12mm @ f/11 focused @ 1' 6" will make everything in focus from your foreground to infinity insuring a sharp image. I see I just parroted Romans good advice, hope this helps.
Randall