[dechols]

Bingo. The whole point of Trello is to mock up some manual end-to-end process. The natural state of this is columns that consist of "Backlog, TODO, Doing, Done". More advanced versions of this look something like, "Vetting, Grooming, Backlog, TODO, Doing, Done".

The circles kind of kill the whole point of a taskboard, IMO.

[bane]

I also usually insert a "Paused" between TODO and Doing in case a "Doing" task stalls out. Rather than putting it back into TODO, I use Paused to indicate that once the issue that's causing it to stall is remedied, it's at the absolute top of the priority queue to get worked on.

[dechols]

Yep. I've seen this too, usually as the "Blocked" state at the end of the process. Items that go in the blocked state need a blocked reason.