When representing classes with their properties, for example in Schema.org, is there a standard method to impose order on the list of properties? schema.org orders alphabetically but I can think of use cases that a different order can be useful.
RDF and OWL do not define an order of properties - in this case you're referring to sequences of assertion axioms or annotation axioms, and these are defined only as sets, with no concept of order.
Most tools will use some ordering criterion in order to simplify life for users and to keep file representations stable (for example, so that minor changes only create small patch sets for source control repositories), but these are conventions specific to each tool.
I can think of different sort criteria being useful for users looking at data, but not on files - the APIs I'm aware of do not reflect the order axioms are seen on file in their im-memory representation, and the language specs do not require it.