Citing sources is surely just putting something down that enables you to find the source again?
I've never considered a "proper" way?!

So, for censuses, I usually quote:
Class (HO107, RG09, RG10, etc)
Piece Number
Folio Number
Page Number
For Civil Registration, I quote:
Type of event (Birth, Marriage or Death)
Year
Quarter
Registration District
Volume Number
Page Number
Anything else, I quote:
The title of the document
Where the document can be found (the repository?)
And identifying marks to enable me to locate the document
The volume/page numbers where applicable.