When I fish small streams I prefer to fish upstream if possible.  Reason being is that casting from the middle as opposed to closer to one side, provides more opportunity for a tangle free back cast.  You can shoot that line to the edges from the middle and hopefully missing the bushes overhead.  By staying downstream from the cast, you avoid sending sediment towards the fish.  You will need to practice stripping line at the speed of the current in order to have the fly ready for the hook set.

Also, practice your roll cast for those times you cannot avoid over hanging branches in your back cast.  Leaving your line on the water, slowly bring your arm back to the position you would come to in a normal 10 & 2 cast, forming a capital letter "D" with your rod being the straight part with a bit of a slant towards the back, and the line forming the curved part of the "D".  Your front cast should be the same speed and tempo as the front cast of a regular cast.