It's hard to say what it should be without more info. I'm basically all stocks with a tiny bit of cash most of the time, but I'm not following a conventional buy and hold or TAA portfolio like most here do.
It's also not necessarily worthwhile to simply add more asset class ETFs to a portfolio. When done, it should be strategic, worthwhile, and serve a certain purpose.
With investing you should think about risk tolerance, goals, simplicity, and manageability of your portfolio. With these basic things clarified, it's pretty easy to build an effective portfolio based on your account mix (amount in TFSA, RRSP, and NR accounts).
As Canadian Ben states, swap ETFs are a useful tool in NR accounts to maximize tax efficiency.
You'll have to share a bit more info if you would like to be pointed in some directions.