An open stance, an outside-in swing path, an open club face at impact, incorrect alignment and fast tempo can contribute to a sliced shot.
Always align your club face to an intermediate and primary target, then step into the shot with your right foot first. Your feet, hips and shoulders should be parallel to the target line.
Staying on plane will greatly reduce your risks of slicing a shot. The butt of the shaft of your club should be pointing at or near the ball in your downswing. If the shaft is above the ideal plane, it will be too steep; below plane, it will be too flat.
A swing that is too fast will throw you off your swing sequence, causing you to slice the ball. Rhythm and tempo are key to a smooth, solid golf shot.
Positioning your body left of the target to avoid a sliced shot will create an open stance, causing the club face to open at impact, inhibiting proper release and resulting in a blocked shot to the right.
Proper alignment so your body is parallel to the target and your club face is square to the target, along with the correct swing plane and tempo, will cure the sliced golf shot.