Communicating insight starts with decluttering
One of the easiest things you can do to improve the efficiency of your data communication is to reduce the clutter on your charts.
Reducing clutter reduces the amount of information your audience needs to process to get to the point. Any verbal narration you add is unlikely to be heard as the audience will still be digesting the chart. The key is to ensuring the key insights jump off the page.
To do this, remove all unnecessary elements, mute any remaining supporting elements and highlight your key insights using colour, contrast and annotations.
Here are the steps I have taken to declutter the left hand chart:
remove the background colour and chart border
use text boxes to label the lines directly and remove the legend matching the colour of the label to the colour of the series
remove all data labels other than those that are integral to your story
colour the most important series and make the others grey
rotate the y-axis label to horizontal and make it meaningful
add horizontal axis labels and plot the data points ‘on tick marks’ rather than the default ‘between tick marks’
remove the horizontal grid lines and add faint vertical ones
increase font sizes