To be honest I think it's all a matter of him going harder to the net and shooting more often. When Z's off his game his shot total always dips... when he scores in the 40 goal range his shot total is near the top of the league. I know it sounds almost too simple but in the end taking 6+ shots a game is going to get you goals.
Right now, Zetterberg's shot total is good for 8th in the league. The bigger problem is that he hasn't been taking many quality shots for much of the season.
For whatever reason, Z doesn't have that explosiveness right now or the same tenacity on the puck. He was never the greatest skater, but he used to always outhustle everyone in the offensive zone--leading to sustained pressure. Now his chances seem to be more or less one-and-done.
On a side note, he wasn't at his best last regular season either. But we were winning games and nobody complained. It wasn't until the playoffs that he was a dominant force out there. Hopefully, he can turn it around here real quick. We're going to need Zetterberg in Conn Smythe form.