I think you should familarize yourself with the basics of the language and its unique pronunciations. The you should work your way up to the harder parts of the language. You should also try communicating with another person who speaks the language and also knows English. Ask them to be critical and point out mistakes you made. After that, I haven other tips.

I think you need to get a penpal in each of those languages.

The best way is to go to a place where that language is the only language, and spend 6 months to a year.

Yes, Rheanna P basically has it. I’ve studied a few languages–around 10 I think, most of them not too seriously–but the only one that stuck–Chinese–came about because I associated with Chinese friends regularly (fortunately where I lived in NYC and LA there are big Chinese populations), and because I spent some time in Taiwan–where I heard and had to use Chinese regularly.
Another tip: when learning vocabulary don’t equate the word you’re learning with the equavalent English word; rather try to picture the thing, or action, in your mind. For example, if you’re learning the word bicycle, picture a bicycle at the same time. For something like “run,” “hit,” “take” picture yourself doing those things. It gets a little harder for things like ideas, concepts, etc., like “learn” or “love.” You’ll have to use your imagination then. But exercising your mind should contribute to your learning.

I studied Portuguese in Brazil for four months, but didn’t learn to actually speak it well until I moved where there were no Americans and I spent all day having to think and speak in it all the time. I think this is the absolute best way to learn foriegn language….you have to envelope yourself in it, the culture of the people and the country. I wish you luck in whatever way you choose. Boa sorte!

The best way to stay or get fluent in any language is to become acquaintances with someone who speaks it. I have been fluent in several languages but the only ones that stick are the ones I use everyday.