Automatically convert copy/pasted text into a certain size and style? (writer and calc)

Hello.
I have been copying text from other sources into a libreoffice document. When I paste the text into libreoffice I want it to be automatically formatted into a certain size and style. How can this be achieved?

Try pasting without formatting (Shift+Ctrl+Alt+V in Writer, Shift+Ctrl+V and select Unformatted text in Calc). This will allow the inserted text to get the formatting taken from the place where it is being inserted to.