Think of a language as a way of expressing meaning. Each language chooses different sounds and arrangements of sounds, to express meaning.
Try to "forget" your native language's grammar as much as you can while you're learning the new language. This will prevent "interference" from your native language.
Identify how your native language and the new language do things differently and keep these in mind when speaking the foreign language.
Review early and often.
Find a tutor to give you feedback on what you're doing correctly and incorrectly.
Keep lists of new vocabulary and sentence constructions. Review as much as you can each day.
Visit a place where the language you're studying is a native tongue, if possible. Speak your own native tongue as little as possible while you're there.
