When your fly cast isn’t quite tracking as straight as you want it to, odds are your casting arm is flying around. To recapture that consistency and hone a smooth, even stroke, Katie Cole of the National Fishing in Schools Program suggests an old, reliable trick.
Tuck something under your casting arm and hold it there. It can be a book, a baseball glove, a copy of Field & Stream, whatever, but make some practice casts with your arm neatly tucked at your side. This will improve consistency and timing.