Drive to San Diego is easier and cheaper. Fly to Vancouver is OK.
If you go to San Diego, park on the US side, walk througn that gate to Mexico (do not drive through the border!). Make sure to arrive at the port in the early morning because they collect the documents in the morning and give you TN/TD in the afternoon.
Make sure bring your passport, degrees, professional licenses, marriage certificate for your spouse, birth certificates for your children. All of these documents shall be in original.