Hmmm, difficult one.... In my opinion the key is "exposure". The more you hear Italian, the more it will stay in your mind and eventually it will come natural to you to "think" with the right sentence structure. I had to do the reverse, going from Italian into English. There is no substitute for living in the country if you can, and "living through the language". You experience a situation, you hear the language that goes with that situation, and next time you are in that situation the language and structures you heard should come back to you...