Start the forward motion of the rod, then, when the line, having passed to the rear, begins to pull back on the rod-tip, and carry the rod forward and down with increasing speed, stopping it when it is a little beyond parallel with the water. Before beginning another back cast be careful to reel or strip in any slack line. The beginner should concentrate on casting accurately and delicately; ability to cover average fishing distances is soon gained without much conscious effort to that end. As for accuracy, the dry fly man cannot possibly over-rate its importance or more profitably seek to perfect himself in any other branch of the sport. Particularly when casting to a rising fish, other things being equal, everything depends upon accuracy.
At this point it seems best to note the matter of the use of the left hand in fly-casting for the purpose of controlling the rendition and retrieve of the line while casting, playing a trout, or floating a dry fly. In brief, the caster should control the line, practically at all times, by holding it in his left hand, as it comes from the reel, stripping in the line through the guides of the rod when it should be shortened, or allowing it to run out through the fingers when a longer line is needed in casting or when giving line to a hooked fish.
It should be understood that the left hand, when used in this manner, need not be held in an awkward position, that is, close up to the reel, but may be held in a natural way at about the waist-line; it is simply a matter of the length of the loop of line drawn out by the left hand between the reel and the first guide of the rod. When this loop for any reason becomes so long that there may be a possibility of fouling it may be taken care of by shifting the rod to the left hand, clipping the line to the handgrasp of the rod beneath the fingers of the left hand, and winding up the superfluous slack line.
The beginner should accustom himself to handling the line in this way when first learning the use of the fly-rod; later it will be all the more difficult to master since at the same time he will be under the necessity of correcting other casting habits which may have become almost second nature. Further reference to this manner of manipulating the line--a most important factor in effective fly casting and fishing--will be found in connection with various subjects such as playing and landing a trout, methods of preventing drag, and so on; in fact, in one way or another the method is essentially a part of practically every phase of the purely manual side of dry or wet fly fishing.