I've been doing the same for the past few years. I started with GTD in Org mode, than switched to Trello and Scrum, but I felt that it wasn't enough and I start

I've been doing the same for the past few years. I started with GTD in Org mode, than switched to Trello and Scrum, but I felt that it wasn't enough and I started mixing the both in Trello. What are some things that you've learned combining the two?