Content for this lesson is taken from:

Dixon, M. R., Jackson, J. W., Small, S. L., Horner-King, M. J., Mui Ker Lik, N., Garcia, Y. & Rosales, R. (2009). Creating single-subject design graphs in Microsoft Excel™ 2007. Journal of Applied Behavior Analysis, 42(2), 277-293. 

Addendum

It has been brought to my attention that Dixon et al.'s (2009) article is missing an important step when creating graphs. This step involves creating tick marks on the horizontal x-axis of all of the graphs that fall directly below the data points. Below is a simple solution to modify your graphs to meet this missing requirement:

1. Hover your mouse over the x-axis of your graph.
2. Right click on the x-axis and select "Format Axis"
3. From the edit screen change your Major tick mark types to "None" and change your Minor tick mark type to "Outside".

This should help line up your tick marks directly beneath your data points.

Thanks to Robert Stromer, Ph.D. for the tip.