I've amassed many LOTR movie translations at https://github.com/genekellyjr/LOTR-Subs, but some yet elude me.
The translations are definitely usable right now as well - feel free to lose a day with almost all Tolkien languages translated! The Releases section has all 3 movies, the main page text describes how to use them/how to apply them/how to adjust them based on combined movie timings.
On the Issues tab are translations I've not been able to finalize. Anyone with experience, please help finish this out! You can also open issues for ones I've missed or ones that are incorrect!
A big one is https://github.com/genekellyjr/LOTR-Subs/issues/6 the convo between Aragorn and Haldir in FOTR; it seems sliced and diced - but I'm confident coherent conversation can be wrung from it. But there are plenty more missing translations - including black speech and Khuzdûl.
And finally, note that I am not able to translate myself, I just find references. Many thanks!