Here are few more common major chord shapes. Learn them from memory and then practice changing between them. This may be difficult at first, so be patient with it.
G
D
F
Practice changing between all of these shapes - C to G, C to D, C to F, G to D, G to F, D to F etc, slowly with your metronome until you have them memorized and can instantly move from one chord to any other chord.
An important aspect of left hand technique is the use of guide fingers. This involves keeping your finger on a string and sliding it to a new position on that string when changing chords.
For example, when changing from a G chord to a D chord, keep your 2nd finger on the 1st string and slide it back from the 3rd fret to the 2nd fret. Like the pivot finger technique, the use of guide fingers helps to create smoother sounding chord changes. The following example makes use of guide fingers.
A strummed rhythm can often be made more interesting by the use of rests as part of the pattern. When playing chords, rests are often achieved by placing the edge of the right hand over the strings. Practice this technique with the following example.