Well, i think i am dedicated in japanese.....
Yesterday , for example , i just played a game for 4 to 5 hours just because it was in japanese....when i am in a train or a bus , i am always reading something in japanese.... and when i am at home i always rent some videos to keep my ears working ....not only dramas , but talk shows, music videos , news ( this one is "interesting") and sometimes , even anime...
Of course sometimes i just forget about any japan realed stuff for some days.....just to relax a little.....it can get you stressed so easy.....
When you are teaching japanese , you have to read all sort of materials, you must read books about a lot of themes , because you need to learn words from every specific area...economy books for example , have some words that you don't see in any other kind of book.
AND you have to know exactly how to use all polite levels.....if you are questioned by your class , well , you just HAVE to answer any question.... when i was just student sometimes my sensei just could not explain some parts of grammar.....
That's a problem when your teacher is a native speaker. They know japanese very well, but when they have to explain a most advanced level of grammar....most of then have problems.....
And because of that i am trying to be a teacher that can answer almost any question , i don't want to make my class feel like i felt before watching a sensei "triyng"to explain me something.....
My main hint is , try to learn using materials that you like. I love games , so i like to read game magazines ( famitsu , v - jump) and i also like j-pop, j-rock and dramas , so i read Miojo ....try to watch comedy too ( smapXsmap) its much better when you are studing and you are "happy"...
Manga and anime are good just in the begining...they are too simple and their language is too far from the reality... after 2 years studing , manga and anime will not help more, so try to read books and magazines that have things that you like , its much more pleasant than "just read any stuff that is in japanese to improve my skills" if you get bored with what you are reading , your chances of "giving up" because its full of kanji are much bigger than when you are reading something that is interesting to you.....well...it works for me.....
Even being a teacher now , it doesn't mean that i can just sit down and relax.....that's always some new word to be learned , so i am always training...always tring to find a better way to "teach".....it never ends....
And i don't give much "shukudai" to my class......they will hate me if i do.....
Edit: I read in some web site the "prepare to be laughed at. nothing is funnier to a japanese person than some gaijin...." and i am tottaly disagree with that.
I think this way of thinking come from otakus that had been 2 years in school , thinked that they already know japanesese enough and " oh yeah!!!i know japanese!! i understand anime , so i know japanese!!!!" and went to japan ( because their parents have a lot of money ) and had "bad impression"when japanese people started to laugh at their way of speaking.
I know by myself some people that talk japanese like in anime and i can say , they will be laughed EVERYWHERE!!!!
Thats because i disagree ....people who think they know japanese because they understand anime will be laugh everywhere , no only in japan , i already laughed at some people several times , since they want to show everyone their "incredible skills in japanese"after studing for 1 or 2 years.......i laughed not because someone have donne a mistake in japanese (since i do a lot of mistakes in english!!!)i can understand that its hard in the begining, but if you know you don't know japanese very well , you know only the basics, you just can't go out and try to show yourself to the world ...some people like to talk like they live in an anime , and they do it in front of real japanese people!!! they think "look at me!!!! i know japanese!!!! i know japanese!!! i am son goku!!!!!"
And believe me guys , i ALREADY see this scene and i can say , its so comic!!
One thing i know is , if you had a good pronunciation of the words in japanese , ( what is seems to be so hard to american people as is hard to japanese people to speak correctly in english, since they have a tottaly different structure of words) you can go to japan without worries , try to pratice the pronunciation of the words , and don't act like an otaku who thinks that japanese people are superior than the others (some otakus really think that japanese are gods!)
And an american will laugh when hear a japanese speaking in english too....so , both sides should pratice more....