Probably one of the first things that I learned when putting was to create a pendulum swing in order to keep my wrists from releasing at the end of my putt.
While this does work well (not only for me, but for most golfers) I decided that I'd try a different approach. Putting seemed like such an unnatural motion to me. And since putting is such a "game of feel," it only seemed right that I try a less regimented technique.
In a regular golf swing (iron/driver swing), the wrists unlock when swinging through the point of impact. When done correctly, it ensures that a ball is hit cleanly and correctly. I decided to see if bringing my wrists into putting would improve my accuracy and distance as well.
From the get-go using my wrists seemed to cause problems- usually balls would be pulled too far left. However, my distance was dead-on, so it seemed like the idea still had some merit. Then I realized that hinging my wrists on an even plane, parallel with my shoulders and toes was the key to accuracy. My accuracy and distance judgement improve ten-fold.
I'm sure a lot of people might say that this violates fundamentals. I would respond by saying that the putt follows the same hinging and release pattern as a normal swing. Furthermore, it uses the fine motor skills of your wrists and forearms to finesse the ball. The traditional putting method uses your bulky, inaccurate core muscles.
For examples of wrist motion improving accuracy, look at basketball. Players couldn't make shots without the final release of their wrists, because it adds a huge degree of precision to the shot. The same goes for beer pong, tennis, or baseball.
Like I said, golf is a "game of feel," so your mileage may vary. But if you're in a putting slump, it might be something to consider.