Visiting a country that speaks your target language is a sure fire way to improve your language ability.
I personally believe it's best to go when you've progressed past the beginner stage as this allows you to maximise your exposure to the language and also utilise what you've learnt as well. You'll leave with a much better understanding of the language and a new found appreciation for your own language learning skills.
Of course, a trip to another country can be quite expensive so this doesn't necessarily need to be a regular thing but how about arranging a trip as a reward once you pass a certain level? You'll be amazed how much harder you can work when you have an enticing holiday in front of you!