As I understand it, it is really easy when learning a new language to develop a horrific accent that's hard to get rid of. Of course, being cognizant of this fact and constantly working on reducing your accent while learning a language should help somewhat. But perhaps there are some things you can do even before learning the language that could help?
Is there anything that I can do before I start learning a new language, that will help reduce my eventual accent?
Research by Patricia Kuhl suggests that even newborns are able to distinguish the sounds of their mother tongue from sounds of other languages. An implication for L2 learners is that exposure to a lot of speech in the language you plan to learn is beneficial even if you do not understand any of it yet: your brain starts developing "a feeling" for the sounds, contours, appropriate speed and accent of the language. I have read that listening to one hour of audio in the target language every day in the first year of study is linked to better accent and pronunciation; it does not have to be concentrated listening, the important part is being exposed to the sounds of the language you (plan to) learn.
One thing is to know something about "accents." For instance, American vowels are "softer" than those of European, or most other languages. For instance, the American "short a" is usually pronounced more like "at" than "father." (The latter is true for European languages.) The American "long a" is pronounced more like "say," whereas the Europeans would use "eh." Knowing that you need to "harden" your vowels in this way (or soften them if you're learning American English) helps reduce your accent. If you're conscious of these things before you start to learn a new language, that would help reduce your eventual accent.
As a "transition point," an American might learn "British English." It's technically the same language, but pronounced in a much more "European" way.
