I have been able to contribute subtitles to this thread without knowing Japanese (I don't even know English well). The subtitles I share are from Chinese subtitles (which you can download here
https://drive.google.com/open?id=1qzkhMO0x4qCKhC_iLjgWv2ZdS1r8Iy2C), for those interested in doing the same. It would be great if many applied this method to generate many more JAV subtitles in English.
1) Drag the Chinese subtitle file wich you want translate to the Google Chrome browser window.
2) Right click on the Google Chrome window and choose the "Transalte to English" option.
3) Copy the generated text.
4) Create a text file and name it the same as the video, including the original extension of the subtitle.
5) Paste the text into this new file and save it.
6) Verify the results viewing the video.
7) Share the file in this thread
In this process I have encountered three inconvenience:
1) Sometimes the subtitles do not correspond to the video (there is nothing left to do).
2) Sometimes there is a mismatch between the video we have and the subtitles (these appear before or after the scene). What is appropriate here is to get the correct video or adjust the subtitle file, whichever is easier for us.
3) Under this method we need to start with the subtitle file already created (in Chinese or another language).
I hope this information is useful for everyone to create their own subtitles.
Enjoy!