Google Drive includes the ability to customise the look of headings and text in your document [see]: Customise your Styles in Google Docs and also to change the default page size [see]: Make more space in a document
Less well known and utilised is the ability to set default style options within Docs and then reuse them for new docs.
Save your personalised options as the default for new documents:
To use your default style in a document:
See also: Save time with a Google Drive Template