Why do fish always shelter in the most challenging spot to cast to? Apparently, they do it to make our life as anglers miserable as opposed to their need to stay alive! The first problem is trying to cast with tight, overhanging cover preventing the normal casting motion. The second is when your casting arm is on the bank side, not the streamside.
Solution: Both tricks require a little bit of practice. When dealing with overhanging vegetation, you cannot execute a usual cast where the fly line whips out eight or more feet above the surface of the stream. For a new angler, doing a “low angle” sidearm cast a few feet above the water is complicated. Simple fix. Flip the necessary amount of line into the current and wait until it straightens. Then, using the friction of the water to load your rod, cast towards the target without any false casts.
In the second situation, your approach to the target put you on the side of the stream where your casting arm must move over the bank and into the trees and bushes instead of open water. Face away from the target to put your casting arm next to the water and away from the bank. Perform a regular cast with one difference. Land the fly on the backcast instead of the forward cast. This takes a little practice to point the rod tip at the horizon, and the target on the backcast, but is easy to master after a few tries. Once this technique is in your repertoire, it will be easy to fish parts of the stream closed out by obstacles forcing you to the opposite bank. One other quick point… this is a useful technique on a windy day. Do the forward cast with the wind at your back and drop the fly on the backcast. The wind loads the rod and adds more “oomph” to the backcast to help cut through the wind. Keeping the backcast low helps as well.