Creating sparklines are pretty easy. You just select the cells with the data that you want to display the trend, then from the Excel menu, choose Insert. Under the Sparkline ribbon, choose the type of sparkline that you want to use to visualize your data. There are three options; line, column and win-loss chart. The line is pretty much straight forward and easy to understand. You then specify the cell that you want your sparkline display. The best practice is to show the visualization next to the data - the last cell after the data on the same row.
You can format your sparklines as per your taste. You can modify the size of the trend line or the color. But what i like the most is to format the sparkline to assist the user to visualize data. This can be achieved by adding points of interest in the sparklines. Under the show tab, you can format your sparkline to show the highests point, the lowest, negative points, the first or the last point. You can add tick marks that show trends over the periods in your dataset. To format your sparkline, select the sparkline to reveal the Design Tab.
For what I do, I created sparklines to help program managers to see the trends of new HIV infections from the districts that they work in; in addition to several HIV care and treatment indicators that needed to be tracked over time. As shown below.
From this visualization, one can see at a glance that an Indicator that is cumulative (incremental) has a problem if the sparkline is not showing a continued upward trend as shown below.
This is another reason why Excel is usually called the king of Business Intelligence
