When working with a tableau desktop the most important thing I learnt was the importance 0f containers, everything should go into containers and this helps to position all of the aspects in your dashboard
Place a container, place in a blank, then place the graph/Text in the container. This helps to keep everything in line and separated.
In tableau we need to make it appealing to the eye, and colour is the best way to do this. using a lower intensity of colour like pastel colours is usually better as it requires less strain on the eye.
When using charts its important that all graphs have padding around them and they are all in line. a good level of padding is usually '10' and this helps keep the parts of your dashboard separated to make it easy to see each graph individually.
Keeping the formatting consistent throughout a dashboard this is as simple as making sure all the axis are aligned to the left and the labels are also aligned to the left.
KPI's should be aligned at the top and only display important data. if there is data that can be displayed as a graph, it should be displayed as a graph not a number KPI
Interactivity is a feature that can help with an Exploratory Viz however this can lose the information of the visualization, Enhanced Data Exploration, Reduced Information Overload & Personalized Views, Improved Decision Making & Trust, Contextual Insights, Efficient Storytelling, Increased Engagement. However just because you can add interactivity doesn't mean you should.
Your viz should tell a story, don't lose it by adding too many "Bells and Whistles"