• Avoid shots with direct sun and lots of shadows (easier said than done), the results are always disappointing.
• In canyons, look for areas lit with reflected sunlight - not only will this reduce the contrast, it will also allow you to take advantage of the orange/pink glow thrown off by the sandstone walls.
• As any photographer will tell you, cloudy days are best for providing even lighting to a scene.
• Use the circular polarizer to help bring out the blue of the sky, avoid heavy polarization though as it tends to make a blue sky almost black.
• Use of a low speed film will give the best color saturation and detail. Low light conditions, however, will force you to use very slow shutter speeds which can result in blurring for hand held photos. A light weight tripod might be worth carrying to get clear pictures in these situations. The photos taken here were all hand held - in canyons the author would brace himself against a wall hold his breath and slowly squeeze the shutter release.
• When composing the scene you are photographing, mentally divide the picture into a grid consisting of nine segments (three rows, three columns). Place the main subject of your photo into the segment which lends itself best to the composition. Photos with the subject in the center of the picture every time become tiresome rather quickly. Experiment with different compositions to add life to the scene.

Other helpful tips:

Keep your camera in a zip lock bag when not in use, it will reduce exposure to fine dust particles which are unavoidable when hiking. For caving or climbing, provide padding around your camera for protection from banging, dragging, dropping, etc. - an old sweatshirt works fine. Take lots of photos, learn from your mistakes/successes and before long you'll only be throwing out 3/4 of the pictures from each roll.