As you enhance your skills, you may want to try to compete against other people in the Community. For that, you have the Iron Viz. The competition is divided into two parts: three qualification contests, the Feeders, and one Final. For the Feeders, only the theme is imposed, and the contestants have approximately one month to find the data and create the best possible visualization. There is one winner per Feeder.

The three winners of the Feeders battle during the Iron Viz Final at the annual Tableau Conference. There is no way to prepare for the Final: build a Workbook from the start, in 20 minutes, live, in front of thousands of screaming people. A jury, composed of four peoples, and the public, vote on Twitter to determine the annual Iron Viz champion. Since 2017, they have also started a European Iron Viz competition. 

I advise you to participate. Not for the purpose of winning, but to push yourself further than you've ever gone in Tableau. You cannot lose; either you win, or you learn.