How to set a default value for a variable?

We tried that, but that does not work when NO value is selected for a variable. We would like to have an “empty” dashboard where everything is setup as we need, and no variable has any value selected. Can that be achieved too ?

Solved it in a hacky way : https://community.grafana.com/t/default-none-dummy-option-for-template-variables/17951/6