Some suggestions I've seen in other threads by Canadians who got approved:
-Depending on the province you're returning to, you might not have health insurance right away, like Ontario. Get in touch with a private insurance company like Blue Cross or whoever, get a quote for the 3 or so months you'll be waiting to get re-enrolled in the health system.
-Provide screenshots of you searching for return flights and rental/house buying. Of course the VO understands you won't be able to buy or rent property until you have PR approved, but showing that you're doing intense research in your desired area is another layer of evidence
-Get your job to email you a detailed list of salary, when you'll start, hours per week etc. That'll strengthen your case
-Get some letters from friends saying they know of your intent to return, you have discussed it with them, it shows you are serious about this. If you have any private message screenshots discussing this to attach with the letters, that would also help
-Are you planning on bringing items other than clothes back to Canada? Stuff like couches, tables, chairs, beds etc? Get in touch with a moving company and get a quote and attach that to your application.
-I've seen others do this. Write a detailed "game plan" of what you and your partner intend to do once PR is approved. Stuff like getting them a SIN, a bank account, a driver's license, helping them get a job, buying a car. Be as detailed and realistic as possible.
Keep in mind, I'm going through this process myself, I haven't been approved at all. This is all just based off things I've seen doing my own research in other threads, and what we intend to put in our application. Otherwise, I think you guys have as strong of a case as other successful applicants I've seen on here and I don't think you'll have any trouble. I hope that helps, good luck!!