Tactics, Positional concepts and sacrifices
How do you improve your rating by 100 points quickly?

To the original poster: Trying to get from 1600 to 1700 is not really hitting the problem on the head. The real question is what is seperating you from higher level play?
You said other than tactics. You should never ignore tactics, but if your think its not your tactical ability holding you back from advancing than what about strategy?
How is your opening and endgame theory? How well do you plan? Check out my chess blog on training and I'm pretty sure you will benifit from it.
www.advancedchesstraining.blogspot.com
Thx guys for the suggestions!
Ur right in studying more in tactics