If you want to polish your dashboard, make sure your tooltips and axis titles are tidy.
Tableau will always create default values for these, but these are often ugly, particularly if you’ve got table calculations going on.
Before you publish your dashboard, go into each sheet and check the titles of your axes. And make sure the structure of your tooltips makes sense from a user perspective.
I find that these two pieces are often overlooked. I’ve been known to overlook them myself. Getting them right will likely pass your users by. But getting them wrong will ensure they don’t forget, for all the wrong reasons.