I run a one-person SaaS company and have been using Trello as a simple planning/tracking tool for my work. For simple tasks, each card is just a title. For more complex ones, I add some notes in the description. My board has just 3 columns: Backlog, In flight, and Done. I spent an hour or so getting it all set up a couple years ago (mostly creating all of the cards for the backlog) and usually spend less than 10-15 minutes a week on the board. As customers submit new feature requests or I find bugs, I add a card and drag it to it's appropriate priority spot in the backlog. Besides that, I review the board every 1-2 weeks to decide if the priority of any items has changed. I try to keep it clean, and quickly archive/delete cards if I decide that I'll never work on them. This gives me a lightweight way to keep things organized without feeling like overkill.