You can save your audience some head leaning if you make your y-axis title horizontal instead of vertical. By default, the y-axis title is vertical in Tableau and it is not possible to change the alignment to horizontal. But with a little trick, you can change that. Take the following simple example. The sales labels for the y-axis title is vertical and might be hard to read for some of your audience.
You can change that by creating a parameter. Click on create parameter and give the parameter an informative name. Choose String as Data type and then write the value which you want to have expressed on the y-axis. In this case it should be “Sales”.
Now you can drag the parameter field in front of Sum(Sales) Measure. The value of the parameter field (Sales) will now be displayed and it is aligned horizontal. Hide the original y-axis title by right clicking on the y-axis and then selecting edit Axis. Remove “Sales” from the section Axis Titles.
Now our y-axis label is horizontal.