After having all kinds of folders for different life buckets (Home, Webwork, Work, Yard, House...) and not efficiently using Toodledo, I had to simplified things. At work we use Agile, and I read about using a Personal Kanban board and it made sense, but I did not want to give up Toodledo.
Doing = current sprint, in progress, work, stuff i am working on
Backlog = next, upcoming, needs to get done soon-ish
Waiting = I know it needs to go on the backlog but not ready to commit to that
Ideas = thoughts that don't quite have a plan yet or are in the distant future
It is much easier for me to use now -- work on the stuff in Doing, look at Backlog and promote Backlog items to Doing. Doing items might have ranking based on priority or due date.
Occasionally review the other two folders and add new task as appropriate.
My recommendation - do NOT over complicate your system or you will not use it.