To save time, you could set the default properties (data labels, legend etc) for all or given chart types. These settings are trigged when selecting a chart from the Data Settings pane.
Click on your email address in the top right-hand corner of the browser and click on
Account Settings in the drop-down
Default Chart Settings and select the chart type you want to set the defaults for.
Make your updates and select
Save. Next time you use the given chart type we will automatically use the chart default settings.