The following general guidelines are taken into consideration while preparing graphs:
1. Title: Each graph should have a suitable title. It may be given either at the top of the graph or below it. The title must convey the main the me which the graph intends to portray.
2. Size: The size and portion of each component of a graph should be such that all the relevant characteristics of the data are properly displayed and can be· easily understood.
3. Proportion of length and breadth: An appropriate proportion between the length and breadth of the graph should be maintained. As such there are no fixed rules about the ratio of length to width.
4. Proper scale: There are again no fixed rules for selection of scale. The graph should neither be too small nor too large. The scale for the graph should be decided after taking into consideration the magnitude of data and the size of the paper on which it is to be drawn. The scale showing the values as far as possible should be in even numbers or in multiples of 5, 10, 20, and so on. The scale should specify the size of the unit and the nature of data it represents, for example, 'millions of tone’s', in Rs. thousand, and the like. The scale adopted should be indicated on both vertical and horizontal axes if different scales are used. Otherwise, it can be indicated at some suitable place on the graph paper.
5. Footnotes and source note: To clarify or elucidate any points which need further explanation but cannot be shown in the graph, footnotes are given at the bottom of the graphs. 6. Index: A brief index explaining the different types of lines, shades, designs, or colours used in the construction of the graph should be given to understand its contents.
6. Simplicity: Graphs should be prepared in such a way that they can be understood easily. To keep it simple, too much information should not be loaded in a single graph as it may create confusion. Thus if the data are large, then it is advisable to prepare more than one graph, each depicting some identified characteristic of the same data.