False casting is a major piece of the overall fly cast.
False casting is the back-and-forth motion of the line/rod that's done before the line touches down upon the water as the presentation is completed. The main purposes of these repeated motions are to simply aim the fly and/or work the line out of the guides while building line speed so you can achieve the desired distance. False casts are also useful when making a drastic change in the direction of your cast and presentation. While false casting is indeed a major part of the entire casting process, there is one issue that some folks can face—they do too much of it!
In many cases, it's impossible to avoid false casting a bunch of times. For example, if you're starting a cast with a foot of fly line outside of the guides and are trying to hit a target 70-feet away, yeah, you're going to need to do several false casts to reach out there. The thing is, anglers can often overdo it when it comes to false casting, thus hurting their efficiency and productivity. After all, the fish are in the water, and if your fly spends a lot of time sailing back and forth through the air those are precious seconds that you're not actually fishing the fly. Over the course of a day, those seconds can really add up. Excessive false casting over fish can also spook them, especially in situations such as sight fishing in clear, shallow water.
The solution is simple—false cast less!
Presentations can often be completed with less back-and-forth than you may be used to. The first keys are achieving optimal line speed and accuracy in your casting stroke. Having a sound, consistent casting stroke will allow for tight loops and better line speed which equals more distance with less false casting. Becoming a proficient caster also means dialing-in your accuracy with a nice, straight stroke so it doesn't take multiple false casts to help aim at a target.
After you've mastered good line speed and a refined stroke, less false casting may simply come naturally. With the rod loading more efficiently, the overall feel and your personal experience will come into play to be a kind of "gauge" as to how far or where you'll be able to place the fly. Folks will sometimes false cast over and over needlessly which is often due to having poor casting mechanics resulting in the line not getting the speed it needs for a clean cast.
Even with a good stroke excessive false casting can be a problem, too.
One issue in some circumstances may be that the line is just not fed out efficiently enough. When double-hauling for distance, don't just feed out small bits of line on each stroke. Learn to let ample amounts of line readily slide through your fingers for added distance. Try doing this on both the front and back casts to speed up the process even further. This allows you to get line out in a hurry and may cut your casting time in half.
Another really useful technique for short to medium presentations is to practice picking up and laying down the line in one single casting motion. To familiarize yourself, start out with a small amount of line on the water, backcast it, then immediately lay it back out on the water on the front stroke. Try doing this along with different combinations like a direction change, a single haul, a double haul, shooting line, not shooting line, etc. This is an especially useful technique because it gets your fly back in the water fast. Not only is it lightning quick, but picking up the line and firing it back out can be much stealthier than false casting right over the fish you're trying to catch.
It's often surprising how much line can be shot out of the guides on a single casting motion with proper technique. Keep this in mind at all times. Sometimes excessive false casting can be more of a habit, and the same presentation or distance can be achieved by simply teaching yourself to end the cast or shoot the line sooner than usual.
Practice, practice, practice!