As was mentioned by another poster, send by mail. If you ship via UPS, they'll charge $50.00 for customs brokerage.
Problems with goods coming into Canada are no different than problems with goods going from Canada into the U.S. We routinely ship both ways. Northbound, the problem is they're mostly looking for guns (we REALLY don't like them in Canada). It's usually a simple task to scan the package if they're suspicious. Southbound is an entirely different problem. They're looking for pot (which we do like in Canada) and Customs usually insists on taking every package apart to inspect it. In the past we had so much difficulty with damage caused by U.S. Customs that we now routinely take the goods ourselves into the U.S., clear through U.S. Customs, then ship from some U.S. point as a domestic shipment.
I thought we might solve the problem by printing up some bright orange labels that said, "IT'S GLASS - NOT GRASS", but wasn't too sure if the customs inspectors had a sense of humour. Now we just take our stuff down to Seattle every few weeks and ship from there. NEVER had any trouble with stuff coming into Canada. That could be 'cause I've never been bringin up any guns.