Default Font replacement

I have changed the default Font in Writer. But how do I do so in Calc and Impress and make the changes permanent. It is a real pain to have to use Format-Character all the time. Libre Office 3.6.2.2

Please take a look to this thread.

Many thanks to Oliver for his clear explanation. Not only did it solve my immediate problem but I learned something about Style, Formatting and Templates as well.