Use a minimum number of digits and avoid extraneous and useless information, such as decimal points in obvious locations. Bar charts Use for data arranged in segments Keep scales simple to make interpolation easy. Do not use different colored bars unless the data change. For example, show historical data in green and estimated data in blue. Order shading patterns from darkest to lightest.
Pie charts Limit the pie to a maximum of seven slices, using colors more than once.
Do not use the same color for adjacent slices. Remember that comparisons between slices are less obvious than between bars. Use a bar chart in preference to a pie chart. Line and area graphs Use to show trends or continuous data. Use a baseline value and scale for maximum effectiveness.