For starters, when you approach the stream, you will need to use a degree of stealth. You also need to be aware that ground vibrations, moving shadows and the sounds of branches breaking underfoot, are all triggers that will send fish into a frenzy that will alert all to your presence.
On sections of the stream where the water is fast moving, these alarms are not as critical, however, they should be foremost in the mind of the angler.
Wading vs. Fishing from the bank
When fishing for fish that are easily spooked, it is always recommended to fish from the bank--and usually well back from the bank edge. However, when the situation calls for you to enter the stream, you will need to make sure you do so slowly and carefully. It is best to find a shallow spot to step into the water. The sound of rocks crunching underfoot travels fast and easily through the stream bed and is just one more way for you to set off an alarm.
A wading technique that I use is the shuffle. Instead of trying to walk on the stream bed, gently slide your feet just above the rocky bottom of the river. With some practice, this technique will become second nature and will allow you to keep your focus on the areas that hold fish instead of looking down to see where you're going. Remember that each step should be slow and quiet.
Direction of the Cast
Here is perhaps the most critical tip for small stream fishing success: Cast upstream. When fish are holding a position, as they do when feeding, they're facing the current. In order for them to face the current, they are pointed upstream. Therefore all the fish upstream from your vantage point are looking upstream, and all the fish downstream from your position are looking directly at you. That is why you are going to cast upstream and forget about downstream casting unless you know that you are out of sight.
Practice these tips on a regular basis and soon they will become second nature and will give you an advantage to your fishing success. Most of all, enjoy the mountains and don't forget to look up once in a while to enjoy the sights, sounds and scents of your surroundings.