Every graph should be properly labelled, with numbers on the x and y axes. There should be a graph title at the top, as well as axis titles on the left and bottom. A properly formatted graph is shown below.
Using a spreadsheet program such as Excel allows you to quickly make a wide variety of graphs.
Helpful DIY – How To Make A Line Graph In Excel (2:35)
EasyClick Academy – How to Add Axis Titles in Excel (watch from 0:41 to 1:35)
EasyClick Academy – How to Change the Scale on an Excel Graph (watch from 0:25 to 1:35)
Steven Bradburn – Adding The Trendline, Equation And R² In Excel (3:14)