Learning a new language is never a bad thing. There are very few I really like as far as the aesthetic elements go, which is why I'm finally trying to learn Japanese. Frankly, it's the only language other than English that I really like the sounds of. English will always be my favorite language, and not just because I know it, but for the variety of sounds it produces and for how wonderfully pliable it is; but Japanese is definitely my favorite spoken language other than English.
I really don't care for a lot of Chinese dialects. I find them too round, bulbous, and monotonous. However, there are some that are softer and rely more heavily upon the pushing of air, and those can be quite pleasant. I hate the sound of Spanish with a passion, though it's an extremely easy language to pick up. I took a little of it when I was younger, but discovered how irritating I found it and stopped. My sister still really likes it. She went to Costa Rica for some months when she was younger on a home exchange program. I like elements of German but dislike others, as with Gaelic.
Chinese and Japanese I think are probably what I consider two of the most beautiful written languages, along with Farsi. I'm discovering that I really enjoy writing in Japanese. I know very little as yet, as I've only been on this endeavor for less than a month, but the more I learn to write the kana, the more I like it. I know very, very few kanji, and most of the ones I've been writing I've been writing with entirely incorrect stroke order (none of my material has gotten me that far, but I'm usually spelling out full kanji/kana spellings of vocabulary words anyway), but it's a joy to write, especially once you begin to recognize the repeating patterns. Given that kanji are basically Chinese characters adapted for Japanese, I imagine this would be much the same with Chinese as well.
I'm still new to seriously studying a foreign language, especially a Subject-Object-Verb language, but I do feel like the last month has taught me a few things: if you can't immerse yourself by being somewhere, obsess over it a little. I've been listening almost exclusively to Japanese music lately, and I had pretty meager exposure to it before, so I've discovered a ton of new bands. I spend most of my time at work listening to them and trying to pick up any words or phrases that I can. I've also been working out again every night, which usually gives me about enough time to sit through 2 anime episodes, so I've been listening much more closely to the speech and trying to pick out stuff from that too. Obviously learning from music and cartoons is questionable, as it isn't "real" language in a lot of ways, but it's something easy that helps you to relax and enjoy the sound of the words without actually studying, and since you can do it during times when you're relaxing or doing something else, it helps fill some of those periods where you naturally just sit around thinking in English. Also, learn some history. Get a few books on ancient history or modern political history, whatever interests you, and read up on it a bit. Having a firmer idea of cultural background will usually help you understand the attitude of the language as well. It's pretty rare that cultural traits don't creep into language to some degree. You see it all over the place in English, and it's extremely obvious in Japanese in many cases.
Also, come at it from different angles. Don't pick something and leave it at that. If you've got a tutor this may be less of a problem for you, but I'm doing this purely on my own, so have little guidance. Anyway, I'm working out of a standard scholastic textbook for my general course, along with some of the audio stuff it provides (audio is always of pretty limited use, especially if you have no trouble pronouncing words in your chosen language), but I'm supplementing it with a hardcore grammar book that's as dense and impenetrable as you could ask for. The two work well together. Thirdly, I'm... er, previewing the Rosetta Stone software to see whether or not there's actually anything to their hype. I'm not convinced there is. It does teach, but not nearly so fast as a textbook, and while it can reinforce certain things well, it has a much more difficult time teaching the necessities of grammar in a language as complicated as Japanese. It does, however, make pretty decent review software, and it's a bit more colorful and lighthearted than a textbook. Maybe even a bit much for me. Regardless, I think a good fundamental principle is to come at it from as many angles as you can afford and have the time for. Almost every book you buy will end up approaching some concepts differently, or give you a little more insight on one particular facet or other, and the things it may approach the same as your other books... no big deal, you're just reinforcing stuff you need to learn anyway.
Anyway, sorry to drone on. Most of that is probably useless to you anyway as you've already got a background in more than one language. But that's pretty much what I've been up to lately, to the exclusion of playing games and such. I'm looking at taking an actual class at some point down the line once I feel more confident with the basics, but we'll see.