I'm also following a GTD-like approach (and I strongly second the recommendation on the book)

My Trello board has the following columns:

- MAYBE - for things that I'll maybe do

- BACKLOG - for things that I decided I'll do at some point

- WEEK - for things that I'll do this week (limit: 8 items)

- TODAY - for things I'll do today (limit: 5 items)

- DONE - move things here once done

Once a week I do a review session where I clean the "DONE" column and reshuffle things in the other columns as needed