How interesting..!! I was just watching a tape of the 1999 Blackpool seminars in which Corky Ballas (in dorky ducky shoes might I add) lectured on the instruction of juniors and juveniles. However, his suggestions are mighty useful to adults as well. One of the things he said that is important for all dancers is attitude. Attitude for different dances are very diferent. But, you have to feel the music, emote to it, and the passion in your heart translates to your feet and body. Well, I paraphrase of course.
But his suggestion, which I found worthy of attention after I stopped sneering at his shoes
, is to pick a song that literally and spiritually moves you, and try dancing to it. Hopefully, e-motion and hand-motion will follow. Better still is to take ballet lessons, or easiest of all, watch the top dancers and imitate what they do with their arms in front of a mirror. You are bound to get it. Getting the arms to move are easier than getting the feet to do the same, and since you already have the latter down pat, I trust, the former should follow in due course.
And if you can get your hands on this video, you must watch the kids that Corky trains. They are fascinating to watch and put me to shame most often with their floor presence, charsima, talent, and athleticism. Boy I wish I had started ten years earlier.. 
Ciao and enjoy.
Sri.