I have gone back to spending quite a bit of time working on tactics. I have been using Chess Tempo for this.
For those who don't know, ChessTempo is a free tactics (and endgames!) website.
But the question remains...can tactics puzzles be overused?
A couple of years ago I read this excellent post on Dan Heisman's website. Written by IM David Pruess, the point is made that you will only be able to get so much and nothing more from studying tactics in any given day.
Essentially the gist of the story is that once you've spent more than perhaps 10-15 minutes on tactics you will not learn anything else that day and additional time is simply wasted effort.
It's an interesting thought, and one that I've been trying to follow.
Does anyone have any different advice that has been given to them by a strong player?