How can I maintain and improve my Japanese translation skills?

I'm a Japanese-English translator, too, and I thought I submitted this post in my sleep! My situation is the exact opposite of yours, though. I'm Japanese and live in Japan, and although I'm probably as thoroughly bilingual as anyone could be, I sometimes feel like my English has plateaued and is degenerating, like you say about your Japanese. I feel like my peak was back when I lived in Canada 20 years ago (gah!), and that now I'm draining away what I saved up until then, so to speak. Like you, I don't have many English-speaking friends here that I see on a regular basis, and I can count the number of times I've had a conversation completely in English with someone these past 14 years or so (ever since I quit my outside job to focus on mom-stuff) on my fingers. It's hard to keep up, isn't it? I know exactly how you feel about going out and trying to find conversation groups. For me this is impossible because my English is too good. And while I, too, like my job and still love reading and writing English, sometimes it feels like such a chore because at the bottom of my heart I've always felt that I'll probably never be as good as a true native speaker beyond a certain level no matter how I try. But you gotta do the best you can with what you have, I guess. One of the biggest reasons why I keep coming back to MetaFilter is for the English "conversation," because this is the only place on the internet that I know where people who "speak" better English than I do gather to "talk" about various topics. In my dream world, MetaFilter would be a bar or something in downtown Tokyo that I could drop by a few times a week to join in the conversation, but then I guess there would be too many brawls out in the back (MetaTalk) for this to be even remotely realistic... Sorry to ramble on like this without a concrete solution. Like No-sword says above, I wouldn't mind if you contacted me about cultural references and whatnot, either. J-E translators unite for better quality!

If you can possibly afford it, your most efficient solution would be to go live in Japan for a couple of months. Presumably you can do your work via email/internet, so you wouldn't have to take time off. Even a couple of weeks would help, but the longer you stay immersed, in my experience, the longer the improvement to your fluency lasts.

I have no Japanese friends. I've been to a couple of conversation groups, but they're filled with 22-year-old anime fans taking Japanese 102, and are consequently useless to me. I'm not in NYC but there has to be better options for this. My first thought would be to call the UN and find out if there are any native speaker groups / activities / etc.

I am heavily reliant on dictionaries to do my work. My vocabulary is pretty bad, essentially middle school level, so I'm constantly looking up words.\ You've got to do the heavy lifting to get your vocab up to mastering the basic 1800+ Joyo kanji, because it will save you time and enrich everything. You don't need to go to Japan to do that. Also, watch Japanese movies and leave the Japanese subtitles on. Study at least an hour a day. Listen to streaming NHK radio. Create a Japanese-language blog.

Again, if your budget allows it, try calling large hotels in Japan (I wouldn't call smaller mom and pop businesses) and have a conversation about rooms and nearby attractions and restaurants, etc.

I'm not in NYC but there has to be better options for this. My first thought would be to call the UN and find out if there are any native speaker groups / activities / etc. Seconding this. New York is crawling with Japanese expats -- try heading to Stuyvesant Street, that weird diagonal street that runs between 2nd and 3rd Avenue around 9th Street; that street is sometimes called "Little Tokyo." There's a Japanese food market there, as well as a bar called "Angel's Share" -- try going and just striking up conversations with people. Or explain what you're trying to do, and they can point you to a group, perhaps.

A series of language exchange partners (people about my own age with whom I go out for coffee/drinks/dinner occasionally and chat about life and weird language quirks with) have helped me to keep my Japanese after moving back to an English-speaking country. Even though I am quite lazy about it and speak a lot of English with language exchange partners, it can still be helpful: at the very least I get some listening in and pick up new vocabulary. You might want to focus more on speaking Japanese, or you might even just make pop culture and slang a key topic of discussion. You can easily find language exchange partners on the internet. I'm not sure what the best local sites are in NYC. And nthing that watching dramas, or o warai bangumi on Youtube, or Japanese news, etc, could be very helpful for you.

The Dutch mother of a friend of mine, who has lived in French-speaking Quebec for over 40 years, swears by daily crossword puzzles as what keeps her sharp in her native tongue, and also on top of new coinages and even pop culture. I don't know if there's a Japanese equivalent to something as awesome as the NYT Crossword, but if there is, it might be worth investigating.

I recently moved back to the US for graduate school after a number of years doing professional and academic J->E translations in Japan, and found myself feeling many of the same things you mentioned in your post. This is anecdotal of course, but here is how I managed to keep my skills sharpened: 1) Spoke with native speakers as much as possible. (Most of my interaction was with friends in Japan over Skype, but I'm certain that in a place as crowded and diverse as New York you can find native speakers that are your age and have similar interests. Do you have a Mixi account? I would be very surprised if there wasn't a Mixi community for Japanese nationals living in NYC.) 2) Found work as a graduate TA teaching Japanese at my university. (Any chance you can teach or tutor in your spare time? Nothing reinforces grammar and kanji knowledge quite like teaching it to others.) 3) Listened to Japanese music as much as I could stand. 4) Added subtitles to a few of my favorite Japanese films to share them with my friends and family. (Excellent for listening practice and learning colloquialisms.) 5) Spent at least an hour every morning, without fail, studying vocabulary and kanji. (http://iknow.jp/ has a great program for this, but it's a little pricey.) 6) Translated short stories and compared them to their professional English translations. It took work, but I feel like I've lost very little of fluency I had when I actually lived there. But enough about me. How permanent is your situation in NY? Have you considered relocating to Japan? I know it isn't a realistic option for many, but if you are concerned about your current ability level and future growth prospects, it may be a good career move. As many have already said, your other best option is to find some way into the local Japanese community. One friend is all it usually takes. Also, you mentioned in your post that you sometimes struggle with uncommon loanwords and colloquialisms in your translations. Are you familiar with the http://www.alc.co.jp/ ? It's my go-to source for natural word connotations and obscure colloquialisms when I don't have a native speaker around to ask. Good luck, and shoot me a message if you'd like any specific reading, music or movie suggestions.