Manual Sort and Subtasks are set on a per list basis. For details on accessing both, see below:
Astrid now allows you to manually order your tasks by dragging and dropping. First, you have to turn on "Manual Sort" in the "Sort by:" drop-down filter.
Once selected, you can click a task and drag it to another position in the list.
You can also click and drag the task into a list on the left hand side (dragging a task to a list from within a different list will remove it from the list it is currently on).
First, turn on Hotkeys.
Click your name in the top-right.
Click "Preferences" on the left.
Mark the box for "Use Hotkeys?"
Once you’ve turned on
Manual Sort (see above), you can also organize your list into subtasks. You can create as many levels of indentation as you'd like by simply pressing Tab while a task is selected. To move an item back one level, use Shift + Tab.
If you drag a top level task, all the subtasks will move with it. If you check off a top level task, all the subtasks will also be completed.