Yep, text file(s). The key is flexibility and putting an effort into something you're going to stick with. A single text file works. Multiple files work. You can accomplish a lot with just the features of the OS, like the window manager, search and shell scripting.
Lots of people like Org mode. I think people who don't like Org mode are partially just overwhelmed. One key is to do as little as you need to and then use the tools available as you find a need for them. One big file works well for that. Or starting with the minimal set of Org mode works well for that. Most people will dive right into the deep and try to incorporate everything right away.
Another trick is just forcing yourself to use something. The most sticky processes I have used were those which came with a job... because I was FORCED. Maybe you should just force yourself to use the tools you have in front of you.
Personally, I like doing small incrementations of my processes and using shell scripts to push those small improvements. If I'm moving slow, then I can back off. If I'm putting everything down to build the most awesome system in like a week or more, then I'm quickly getting myself stuck in a corner.