If there is more than one line on a graph, choose colours or marks on the lines that are easy to distinguish from each other. Make connecting lines clear and easy to distinguish from other lines on the graph. Legends that explain what each of the lines represent should be set well away from the data lines. Use a sans serif font for all text to make it easy to read. Don't extend the horizontal (x) or vertical (y) axes beyond what is necessary to include your data. If your data range in value from 0 to 46, consider having the axis between 0 and 50, but not more than that.