I use Google Translate for them since the source doesn't have an official title translation. I'm uncomfortable attempting to do them in English-Japanese, so I just leave them as is; if you look at older galleries I've posted, I used to put that in the Uploader Comment to preface that it would be wrong. I've attempted to correct the titles from the initial MTL and clean them up, but they got changed regardless, so I stopped bothering. I'd love to do a proper title from the get-go, but I'm unsure how. If you have any tips or suggestions on how I could do it better, I'd be glad to hear them.
Honestly just use the japanese name but type it out in romanji, that's what 90% of other translators do anyway. Yeah it would be nice to actually know what the actual name of the work means in english but if you can't do it without it sounding cludgy or cringy as fuck, just don't bother, we're okay with that. At least with romanji you can search for parts of the title even if you don't understand a lick of japanese as opposed to leaving it in kanji, which is a nightmare to find the right characters conventionally for western users.