I'm not a 1600 player... 2100
... but I can assure you that the 500-point path from 1100 to 1600 is quite a bit easier than the 500-point path from 1600 to 2100; and FAR easier than the next 500 points up to 2600.
Study tactics, tactics, tactics, model mates, tactics, pawn structures, tactics, typical endgames, tactics... play over your games and analyze them, ESPECIALLY the painful losses. Get stronger players to tell you where you are going wrong. Play slow games. Blitz is fun, but you will learn a lot more if you take your time and THINK.
I decided to put a goal of 1600 in one year from now.
I'd love to hear from 1600 rated player how they got there and how long it took them and what was the main thing they did well in to get there..
Thanks for even reading this :)