how to Create the Correct Chart

Following are some 'Best Practices' that you should use while creating the best chart for visualizing the data:

• When using time:
• Set it on the horizontal axis
• Time should run from left to right
• Do not skip values (time periods), even if there are no values
• Remove clutter (any excess information, lines, colors, and text that does not add value)
• Sort your data in ascending or descending order by the value, not alphabetically (to enable easier comparison)
• Don’t use a legend if you have only one data category
• Use labels directly on the line, column, bar, pie, etc., whenever possible, to avoid indirect look-up
• When using monetary values in a long-term series, adjust for inflation
• When using colors:
• Don’t use more than 6 colors
• For comparing the same value at different time periods, use the same color in a different intensity - from light to dark
• For different categories, use different colors - The most widely used colors are black, white, red, green, blue, and yellow
• Keep the same color palette or style for all charts in the series, and same axes and labels for similar charts to make your charts consistent and easy to compare
• Check how your charts would look when printed out in grayscale. If you cannot distinguish color differences, you should change hue and saturation of colors
• 10% of men have color deficiency - Use some tool like Vischeck to test your Chart - Best is to use the color palettes that are friendly to color-blind people
• Don’t add too much information to a single chart - If necessary, split data in two charts, use highlighting, simplify colors, or change chart type

See a BAD chart here:

DEMO of removing clutter from a chart:

One good resource to select the best chart is the below strategy created by Dr. Andrew Abela:

Sources:

Eazybi.com

Extremepresentation.typepad.com

Designingforanalytics.com

Quora.com