Important Factors In Fly Fishing

Learn to Read the Water

Fish will behave differently depending on certain water conditions that change depending on what season it is.  This includes the temperature of the water, what the weather is like, and the volume of the water.  If you want to become a successful fly fishing expert you'll have to learn how to read the waters where you're fishing. 
 
Some of the things that you'll discover as you learn to read the water are (1) during non-feeding periods, fish can still be encouraged to strike if they are in a deep pocket of water, and (2) when fish are feeding they are usually found in the shoreline of runs of pools and in moderate water pockets.

Another important factor in fly fishing is that of water chemistry plays a big part in the health of fish, the location where they are found, and how successful you are at catching the big one.  One of the most important aspects of water chemistry is pH.  In scientific terms pH can be defined as: the negative log molar concentration of hydronium ions in the water.  In simple language pH is the measure of the acidity or basicity in the water.
 
pH is typically measured on a scale of 1 to 14.  A pH of 7 is considered to be neutral.  pH totals of less than 7 are acidic while a measure of over 7 is considered basic.
 
Most fish are able to tolerate a wide range of pH in the waters where they live.  This is because they have the ability to regulate their internal levels of pH.  This is accomplished by the fish constantly adjusting the ratio of bases and acids within their systems.  They make these adjustments by expelling any excess acids in the urine and also by controlling their breathing. 

The faster a fish breathes the faster carbon dioxide leaves the blood, thus raising the level of pH in the blood.  However, most fish are eventually tired out by this constant regulating of their system.  If the fish lives for too long in an environment that is too acidic or too basic it will become unable to manage its own system chemistry.  When this happens the fish will stop feeding and eventually die.

Keep an Eye Out for Structures

When you're looking around for a place to cast your line to do fly fishing it's important that you look around for structures both on and in the water.  This can be a large boulder or stone, a log that is submerged, or the tail end of a pool.  These are great places to find fish since they don't want to work very hard when it comes to looking for a meal.  Fish will congregate near structures, where they will set up feeding stations.

Keeping Track of Patterns

 One thing that you can do when fly fishing is to keep a log of your favorite fishing area each time that you fish.  Make note of the problems that you're having as well as:
" weather conditions
" water temperature
" current
" the size of the fish that you do catch
" the time of day that you fish

After a period of time you may notice a pattern occurring, such as the lack of bites on days when the water temperature is too hot or too cold.  This will be your indicating factor of what changes you have to make to break your unlucky streak, such as changing the time of day that you fish or changing the side of the lake that you fish from.