Concentration
Watching and focusing on the ball closely for long periods of time is one of the most common difficulties among cricketers, whether junior or international. When Ab De Villiers, South African Captain, is dismissed, he regularly finds a drop of concentration to be the fault. While watching the ball might seem incredibly easy and a given when batting, many beginner players do not watch the ball as closely or for as long as advanced batsman. The batsman should be fiercely concentrating on watching the ball out of the bowler's hand onto the face of the bat. Many amateur batsman don't focus on the ball coming out of the bowler's hand and instead, simply look at the general area. Watching the ball onto the bat, allows you to effectively observe pace, swing and spin execute the correct shot.
Playing every ball on its merits.
This is the frame of mind where the batsman watches the ball,and plays it accordingly. If the ball is on a good line and length, the batsman won't try and ramp or hook it for six. Playing a ball on its merits is particularly important in longer forms of the game where keeping your wicket is essential to a high score.