A whole "cure golf slice" industry has been established in recent years, worth billions of dollars. If you consider the fact that more than 80% of golfers have a slice problem, then you won't find it hard to understand why this has turned into such a big business. With all the top manufacturers coming up with new models that provide straighter and longer shots, why do players keep on slicing? Now that's a very reasonable question coming to show that slicing depends mostly on the swing, not on the equipment. You can buy a golf set for $10000 and still be an absolute slicer.
To cure the golf slice, you must first get an understanding of how slicing occurs and what's the actual mechanical explanation of the problem. Slice is a term describing a specific left-to-right type of trajectory of the golf ball for right-handers, the opposite is true for lefties. Either way, a slice ends up right (or left) of the target line. Every golfer tries to hit the ball squarely and straight, but if the club face is slight open at the point of action in one direction, it will cause the ball to spin which will ultimately make the ball go left or right. Right-handers spin the ball clockwise when they slice, the friction which results from this spin makes the ball go to the right.
The most basic principle that will help you avoid the slice is to try to have the club face squared to the swing path at the point of impact. As mentioned, an open club face will cause the ball to spin, resulting in a slice. The most common reasons for an open club face are: incorrect grip, wrong setup, poor body action (swing). Three main grips you can have on a club - overlapping grip, interlocking grip, finger grip. The right pressure, along with ideal placement of the hands on the handle, will result in longer and straighter shots. Make sure your motion is controllable, it's all about gently swinging the club.