Set Default values when creating a meeting

Every time I create a meeting I have to change the same values. Phone area UK, video on, audio on, continuous chat off. 

How do I set these to be the defaults so that when I create a meeting, I just have to enter the minimal information. 

I can use a template, but that's not what I want. I want to set the default values so they apply to every meeting. I have a plug-in for my email client. It'll create the meeting, but then I have to go back and edit the parameters.

How do I change the defaults?

Thanks