I've added my own extra rule that I have to retain any existing knowledge from row to row, so green letters have to stay in place, yellow letters have to be included (and moved), and grey letters can't be used again (not that you'd generally want to).

I think that keeps it much more fresh from day to day, although I haven't thought too hard about meta strategies. I always input the same first word but then go from there just using what comes to mind first without violating any of my current "rules".