I have always seen the placement of Personal & Confidential on envelopes as follows:
PERSONAL & CONFIDENTIAL
Ms. Jocelyn Smith
Any City Any Province/State Postal Code/Zip Code
I would recommend bolding and capitalizing Personal & Confidential to make it stand out.
At one place I worked we were told by the post office to put the City, Province/State, Postal/Zip Code information on one line as follows for better mail processing:
OTTAWA ON K1R 1A2
I was also taught that the proper spacing should be:
City (one space) Province/State Abbreviation (two spaces) Postal/Zip Code.
Punctuation is optional as either way is acceptable:
OTTAWA, ON K1R 1A2 or OTTAWA ON K1R 1A2