I use Star for the task that I will tackle on that day. When I am working with Projects, I add a star to the Next Action task so that it shows up in my Star View.
During the day I use the Star view to focus me on the task I committed to finished on that day. This includes individual task that are not part of a project as well.
On the iPhone, the Starred view does not show the sub-task with the star on them if they are Nested. On the website this works fine.
This forces me to show my task "in-line" on my iPhone in order for the sub-task with stars to show up but breaks the way my other views look on the iPhone.
I am having to constantly switch between Nested and In-line to keep things neat as I use the iPhone app.