Hello to all you codementor people out there!
I have had the honour of guiding many people through their own Tableau ups and downs and have slowly realised that there are so many "little" things that you could do to turn a visualisation from meh to EPIC. They are all out-of-the-box in Tableau and pretty much always overlooked. This series of articles will delve into the hidden gems of the platform and help make your next dashboard a dazzling one.

What is Tableau?

Tableau is a powerful data visualisation software that is a fierce industry leader in its sport. I started learning it in 2017 and have since become a Certified Professional with a cool portfolio. In 2019 I discovered coding but I still use Tableau from time to time, and help others on their journey. The practices I have learned also have transferred to developing visualisations in code, and hopefully the code versions also look as pretty.

Setup

I will be using the Superstore dataset, a standard in any Tableau version. Let's open it up and you'll land here (I am using 2021.2):

To follow along with me directly, open up the "Sample - Superstore" there on the bottom left.

Overview

We'll do a quick introduction to the various parts

These are the placeholders for your rows and columns that will build your visualisation. You will mainly be dragging pills from the left pane onto columns and rows. You can have any number of pills on either column or row. Now let's get to discussing pills.

Based on your data source, you will see a collection of fields here. When you click and drag a field to Columns or Rows, or Marks or anywhere else, they will turn into a blue or green pill, hence the name. Now, what's the difference between blue and green?
Blue is, in general, a Dimension or Discrete value. It determines the level of detail your visualisation is broken down with. For example, here the view is broken down by Region only:

Whereas now it's broken down by Region AND Customer:

There are more rows now, and each row represents a level of detail on which all other calculations depend.
Green is, in general, a Measure or Continuous value. these are the values that will be aggregated to make the bars, pies and donuts that you all like to see. For example, Sales by Region can be represented as such:

Notice how the Sales pill is wrapped in a SUM aggregation. This is telling me that the bars represent the SUM of sales for a given region. SUM is an aggregation and an aggregation is mainly how a measure is represented.

NOTE: Dimensions CAN be green and measures CAN be blue. This is more advanced stuff for another time. But now let's focus on the bar graph we have a little bit above.

It looks ok for a bar graph I suppose. There are gridlines behind the bars which aren't so necessary. The bars are a bland blue color. The axis is telling me the range of value of sales, but I don't know each individual value.

Format Reset

I like to do this on every one of my workbooks. Something to keep in mind is the Data to Ink ratio, where the simpler things are, the easier they are to read. I like to get rid of as many weird lines as possible. To do such, go to Format > Workbook at the options at the top:


You will see these options. These are workbook-wide formatting rules for fonts, colours and lines. Within each view, or sheet, these can be modified. But it's great to have a reset.
So let's get rid of those lines!

Now our bar chart looks a little whiter:

On the Marks Card:

let's add the label, by just clicking and selecting "Show Mark Labels". Then you can format the label nicely. I like to pick a smaller font size, even like 7px (which isn't a standard option, but you can type in 7 and hit Enter).

Onwards to the coloring. I like to go with a lighter colour and a darker border. And maybe even a bit transparent. But play with what you like:

Now, on the graph itself, I can right click on the axis and uncheck "Show Header" to remove it. Above the regions, the title "Region" is quite superfluous, so you can right click and say Hide Field Labels for Rows. (To get them back is a bit tricky. You have to go to Analysis > Table Layout > Show Field Labels for Rows
Let's go back to Format > Workbook, because I'd like to change the Font Size for the Worksheets to be 8, and also change everything to Arial (personal preference)

The only thing I wish we could do is default align all our titles to center! If there's a way, let me know. But if I double-click on the "Sheet 1" I can align it there.

I don't have to rename it here, though, because its property is the name of the sheet below, so I can just rename it below:

Now let's see the graph:

Looking better. I want it to take up all the space, so I can change the "Standard" option at the top to "Entire View":

And BAM, it's big. Now the labels don't seem like currency values. It is "Sales", after all. So here's the best trick in the book. Right click on the Sales pill, go to Default Properties > Number Format and this is now a global formatting for this measure (which can be edited on a per-view basis as well):


And voila! We have achieved a nice-looking bar graph with fewer lines and distractions.

Conclusion

We have gone through the process of making a simple bar chart look more appealing. Along the way, we have learned how to format a workbook globally, as well as individual measures. These little tips and tricks will give you an edge in designing really nice dashboards. Join me in Part 2 (soon) where we will explore more advanced tools to make some really stand-out kpis. Until then, happy graphing!

~ Sean