I don't pretend to be a player of any serious caliber....more likely still a rookie... but what seems to have helped me is just going back to the principles. When I play good for a while..I seem to start getting overconfident and start whacking the balls harder and picking up the pace unnecessarily.
The change is so gradual and subtle that I've had hard time picking it up.
It's also like self-growing problem...the more I miss, the more frustrated I become, the less focused I become, the more I miss..
What has normally helped me then is simply to walk away... I've usually taken some time off....not play for a few days...a week...even two... This has helped me to then approach the problem without the frustration.
Last time this happened actually not too long ago...I stopped playing for full 2 weeks....during this time I went to see both Amsterdam Open and World Poolmasters to see how the Pros do it.... and it was almost like a revelation...I (re-)discovered the fact that the pros hardly ever bang the balls around with a lot of force, they let the balls do the work for them. They also don't let the pace get out of the hand.....even if it is an easy rack, they take their time to shoot every ball properly instead of just trying to run out as fast as possible.
This kind of studying of other players has helped me as well to identify technique problems in my own game. For example I just realized that I had been playing with the wrist of my backhand turned too much outside. When I then stroked, the wrist tended to start rotating leading up to the fact that I didn't hit the cueball where I wanted to. Now that I know it, I've paid extra attention to it and suddenly those long pots just miraculously have started to drop!
Well....I am sure everyone has their own reasons for slumps....I seem to have found a reason for most of mine....inside my head. Luckily I seem to have found a relatively effective way to deal with it as well.
Live by the KISS-principle!
cheers,
Kimmo