Would you like to know how to improve your chord changes? Of course you would! Is there some secret formula or magic trick that will make your fingers quicker? No...
but there are some "muscle memory" exercises you can do to strengthen them.
This will make a big difference in your playing.
Yesterday I gave one of my students a series of simple chord progressions to practice.
As he was playing through them I noticed that he could transition easily from the C chord to the Em chord, but he had difficulty moving from Em back to C.
That's because it's easier for the hand to close than open, and moving from Em to C requires that you stretch and open your hand.
The problem he was having also affected his timing so that he was unable to keep a steady 4/4 rhythm.
Repetition is the key to improving chord changes, but there are some ways to speed up the entire process.
One of the first things you need to do is to practice being observant when you're playing.
Take mental notes of any difficulties you are having so that you can create your own improvement plan.
Many beginner guitar students seem to ignore the importance of listening to themselves.
But this is an essential ingredient to becoming a better guitar player.
After identifying the problem my student was having, I was able to provide some simple exercises he could do to improve his chord changes.
The first exercise was to focus on only these two chords by using a chord drill.
SIMPLE CHORD DRILL:

• Strum Em and begin counting to four
• Move to C BEFORE reaching the number four
• If you can do this, reduce the count to three
• When you can easily move from Em to C in three beats...
  
• Try it in two beats, then in one beat.
  

It's important to keep a steady count.
Use a metronome to prevent the tendency to slow down your count.
The next exercise is called "chord bouncing" (my own term)...
CHORD BOUNCING

1. Strum any chord (let's use C Major)
2. Lift all your fingers up off the fretboard, while still holding the shape of the chord, and strum the strings again (open)
3. Set them back down on the strings and strum the chord
4. Practice strumming this with a count: 1 (fingers down) 2 (fingers up) 3 (fingers down) 4 (fingers up)

Your goal is to place your fingers exactly where they need to be.
Try to set all your fingers down on the strings at the same time.
This is a great exercise for training your fingers to memorize a chord shape.
Continue practicing these exercises until you can change smoothly from one chord to the next without losing the beat, or shape, of the chord.
Be careful not to over due it! You only need about four or five consistent repetitions every day to improve your chord changes!