I use Trello in a number of ways in the business. From helping manage my personal tasks to managing the sales pipeline and project management. I use it via the app as a brain dump to get ideas out of my head into a list which I then organise via the cards into their priorities. Saves me having to juggle stuff in my head knowing its in there.
I use it to manage my sales pipeline so see visually the stages. Likewise for when I manage different types of projects. The visual card system helps me keep on track.