Let's look at essential chord changes for the G chord and tips to help you. This lesson is from the Andy Guitar Beginner Guitar Course.
D to Big G change
For this change we can simply use the ‘Big G’ here because it sounds great and the change is easier. Use your 3rd finger as an anchor for the D to G chord (on fret 3 string 2) form the G major shape and tuck the little finger under the 3rd finger on fret 3 string 1. All in all this should be a normal D major to Big G change.
G to A change
There's no anchor finger for this change, so you just have to lift your fingers to change.
TOP TIP. Try and memorise the shape your hands make for each chord... How can we do this?
Make the G major shape (any variation) hover above the string without pressing down
Change to the A major shape
Back and forth while hovering is helping to commit to muscle memory and save your finger tips from hurting by constantly pressing down!
Try the 1 finger A chord or 3 in a line variation!
Final Tip is to do what feels right for you. Now there are more options and variations to consider, we must start to do what best works for us.