How do I prioritize tasks?
The task list is ordered by priority: the tasks at the top are assumed to be more important than those below.
You can reprioritize tasks by dragging and dropping them to a new location. The straightforward way of doing this is clicking on a task and dragging it to one of the dotted "slots". You'll also notice that when you begin to drag, a floating panel appears in the right sidebar. This panel has shortcuts that will immediately move a task to either the top (most import) or bottom (least important) positions of the project, or to any milestone your project might have.
Task group buckets can be moved in the same way, which will move all of its tasks collectively.