Google Translate has been pretty good.
I did my own machine translation of
Venus Blood Abyss by just dumping it into google translate(through chrome).
If I did some preprocessing beforehand and did some editing after it would be even better results.
But for the time I invested which was a few days work mostly to extract, format and patch while getting things working without errors it's pretty decent.
Much better then if I were to use just Translator Aggregator. I already did a playthrough of the translation and I was pretty satisfied. Yes you do get some weird shit.
If you are going to use the dumping method, make sure to translate names, locations and other tricky terms before dumping it into google.
Also Google works best when you merge the sentences into a line with no weird spacing and line breaks, punctuation is not a problem and can be left as a continuation or as a new line. You may need to do some regex tricks with Notepad to get the format right while still maintaining the position information of the inserted line.
After that you can dump a 7k lines .txt into chrome with translate to english you get from translating sites on. Just split your text into 7k chunks and wait for that to finish, if you go more than that the translation tends to come to a crawl.
After that look at the page source with F12 go to part where the translation is and use Edit Html option and copy that into a text file and remove the html tags and do some format cleaning for whatever google messed up.
After that you might want to read through it and edit things, but who has the time for that?
After its just patching it and formatting it to get it to work in the game. Some things can get tricky like keeping track on which lines go where and word wrapping issues and lines going beyond the text box.
Some games support generating a new text box to continue the text so use that function if you can.
For manually translating things line by line how you organize things and what tools you use definitely helps. I still recommend having all text dumped somewhere even if you are doing a playthrough of the game.
Some tricks that can help is having text to speech and voices enabled, programs that have text to speech support like VNR or NextOSD you can also filter by name with regex so you can filter voiced characters.
I also recommend learning hiragana and katakana, since it is phonetic together with text to speech it will help you tremendously, it also helps you against some Engrish traps that screw up translators.
For Interface Translations the Capture2Text program is perfect in capturing text that cannot be extracted with hooks.
Cheat Engine and
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are also great to make your own hooks and get hard to get text like tooltips and descriptions.