I set aside 5-10 minutes a day to review French things - I usually have a range of things available, whether it be a set of flashcards on my iPhone, writing a notebook entry on this website, a book of written practice exercises, listening to a news clip, etc...

Then I try to take a class from an instructor once a week. I can usually only fit it in on the weekends or early in the morning.

I'm not making the progress I would like, but I'm making more than if I wasn't doing anything!

From personal experience, I think one of the most important things is to develop a structure if you're beginning a new language and to stick with it on a daily basis. It doesn't have to be crazy, just something resembling a routine with a light at the end of the tunnel.

I'm currently using Assimil for learning Russian. I also have somewhat of a busy work/school schedule, so one thing I've learned quickly is that my mind doesn't like to learn information in larger chunks while I'm preoccupied with other stuff throughout the day. To combat that, I take an audio lesson out of the text, split it into to smaller parts, and put each smaller part on repeat-one. By the end of the day, I would've covered a lesson in its entirety using nothing but dead-time. (aka, no effort)

Once I have a bit of free time in the evening or the following morning, I'll spend it reinforcing the information which I've learned passively. The latter usually takes no more than 10-15 minutes. It's kind of like slowly gathering pieces of a puzzle and then putting them together once you have them mentally laid out. Afterwards I'll wash, rinse, and repeat with the following lesson.

As for how this relates to you, since Assimil doesn't have a Korean course in English (they do have a French version), I recommend finding some course that can easily be tailored to fit your hectic lifestyle; one that's manageable easy in smaller chunks and doesn't require much sit-down time. (If not a course, then at least a no-BS podcast.) After that, it comes down to finding a routine that works and sticking to it. Then again, YMMV. What works for me might not work for someone else

I've heard that it's really helpful to try and surround yourself with the language. For example, labeling things all over the house in Korean with sticky notes (for instance, write 냉장고 on a note and stick it on the fridge), listening to Korean podcasts or music in the car on the way to work or school, reading Korean books or news articles while you eat breakfast or before you got bed, etc. These are things you can do (especially the sticky notes) that don't take much time but can really help you learn :)
Hope this helps! 

If I don't have a lot of time, I tend to listen to podcasts/lessons on my ipod to keep my listening comprehension strong.

i listen to KOREAN LESSON MP3 always in the way to university or to home ... 

in 2 hours i learnt how to read and write in korean its easy you have just to listen to the pronunciation and need more vocabulary :) 
fighting !!