I think most fly fishers use aerial mends whether they know it or not, probably just develop their own style on getting the fliees to the fish, unless they were professionally taught.
I probably use some hybrids of them.
Here is an article on some:
Presentation Casts
This article gives an overview of the most common presentation casts, how to perform, and when to use them. The title is slightly deceiving, since many of the techniques discussed here are actually mends, not casts. The difference is purely academic and I won't bother differentiating here. The fish don't care and neither should you.
In fly fishing we generally want to present the fly in a manner as close to the natural as possible. Naturals, however, don't have a long string tied to them. In moving water, current pulls the line, which in turn affects the movements of the fly on the water; this is called drag. Drag is generally undesirable, so there are a number of techniques which strategically place slack in the line and thus minimize the affects of drag.
A quick word about slack line. The more slack in the system, the more difficult it is to set the hook properly. This means that you want the minimum amount of slack you can get away with to get a drag free drift.
These casts are more-or-less organized in order of difficulty.
Pile Cast
The most basic slack line cast is the Pile, or Puddle, Cast. To execute the Pile Cast, make a low back cast and a high forward cast. Immediately after the stop, rapidly lower the rod tip to water level. The line should land in a large heap in front of you.
This is a great cast in back eddies, swirling, or otherwise complex currents where lots of slack and not a lot of accuracy is required.
Advantages: Easy to execute, lots of slack.
Disadvantages: Poor accuracy, difficult to control in wind.
Wiggle Mend
To perform the Wiggle Mend, move (wiggle) the rod tip from side to side after the final forward cast stop. The larger the movements, the larger the wiggles will be.
This is something of a catchall presentation cast because it works in many situations. You can be reasonably accurate and put a lot or a little slack in the line for a variety of different currents.
Advantages: Simple, reasonably accurate.
Disadvantages: Slack is not targeted, can be difficult to achieve distance.
Reach Mend
To perform the Reach Mend, simply move the rod 90 degrees to the cast after the final forward cast stop, while allowing slack line to slip through your fingers, then you may return the rod to it's normal forward-pointing position or follow the speed of the drifting line with the rod tip. You can do the mend just fine without slipping line, but it makes it more difficult to place the fly accurately.
Use this cast when standing close to an interferring current while fishing in slower water on the other side (mend upstream), or when standing close to slow water fishing in faster water on the other side (mend downstream).
Advantages: Moves a lot of line, can provide a long drag-free drift, accurate.
Distadvantages: The slack may be placed only at close quarters.
Aerial Mend
The aerial mend is one of my favorite presentation casts. To execute, move the rod tip briskly to one side and back directly after the final forward cast stop. The sooner after the stop you make the side-and-back movement, the farther out the mend will be. Keep in mind that the farther the mend, the more power required during the initial sideways motion.
This is a great presentation cast because it can be very accurate in fly placement, slack placement, and amount of slack. Use this whenever you need slack in a particular place, as when casting over a current to slack water (mend upstream), or when casting across slow water to fast water (mend downstream). Want to get really fancy? Try putting slack to both the right and to the left in different places.
Advantages: Only the slack you need only where you need it.
Disadvantages: It can take time to get the timing down, difficult to place slack near the leader.
Bucket Mend
To perform the bucket mend, move the rod tip up, then down a few moments after the final forward cast stop. This is like a vertically-oriented aerial mend.
This is a great technique for downstream drag-free presentations or whenever you need a lot of slack in one small area, like small back eddies.
Advantages: Lots of slack in a small area.
Disadvantages: Difficult to place slack accurately.
