What are some common barre chords and how can they be played effectively on the guitar?

Common barre chords include the major and minor shapes, as well as the dominant 7th shape. To play them effectively, use your index finger to press down all the strings at a specific fret, while using your other fingers to form the chord shape. Make sure your index finger is pressing down firmly and evenly across all the strings to produce a clear sound. Practice transitioning between different barre chords to improve your technique and fluency.