How do you set up a fly and bubble for fly fishing?

To set up a fly and bubble for fly fishing, start by threading the main line through a bubble float, which acts as a strike indicator and casting weight. Attach a swivel to the end of the line to prevent line twist, and then tie a leader line to the swivel, typically around 2 to 4 feet long. Finally, tie your fly to the end of the leader. Fill the bubble float with water to adjust its buoyancy, allowing it to cast further and keep the fly at the desired depth.