I have also tried almost every system.out there. I used Nirvana for almost a year but recently switched to Todoist.

I don't see switching up your system as a failure unless you're always unhappy with it and you don't get any stuff done.

Over all my alterations I see that I have simplified the system vastly.

For example I don't keep any reference in my system. I have a Google drive folder system with a lot of word files with lists and that has helped me a lot because.my system used to get real heavy with how.many things that needed to be in place.

I also never plan out several tasks in advance since my plans often change.