When I say linguist I do not mean someone who studies complicated theories about language. I just mean someone who can speak more than one language and who enjoys doing it. Usually the two go hand in hand.
Native speakers of English are at a big disadvantage because there is less incentive for them to learn other languages. This may soon change, however, with Spanish and Chinese looming larger.
The key is to make the learning experience enjoyable and interesting. Most language education destroys the fun by focusing on speaking correctly too soon, or by teaching theoretical grammar explanations.
There is no substitute for lots of exposure through listening and reading. But then you need interesting content and a good system for retaining vocabulary otherwise it is just frustrating. In learning my nine languages I feel I have kind of worked that out. I am interested in hearing the experience of others in language learning.