I have residences in both the Philadelphia, PA and Vancouver, BC suburbs. And I’ve shipped A LOT of audio and personal things back and forth to Canada over the past decade.
First, if at all possible, NEVER, EVER, EVER use UPS!!! They are the absolute WORST shippers between the USA and Canada of any of the typical outfits. They often hold up your shipment in Customs for days, weeks, or in some cases, months. They have the HIGHEST rate of damage your shipment, combined with the WORST record of payout, and the absolute, lead pipe, worst, HIGHEST fees and charges of any of the shippers. I’ve had shipments come in where UPS trickles in fee after fee after fee over the course of several months which left me utterly worn out.
Best way to go is actually same as shipping domestically. For smaller items, use USPS / Canada Post. For larger items, FedEX Ground.
Concerning Customs fees, charges, taxes, etc., Canada is infinitely more on top of this than the USA. Believe it or not, most of the time, I get stuff delivered to my American residence from other countries, and that's that. No additional charges, no hangups, no paperwork, nothing. That NEVER happens in Canada, they always get their cut.
One other thing, if you have a FedEX account, sometimes, there’s not as much difference between FedEX Ground pricing and FedEX Express as you would expect. Of course, Ground is still cheaper, but it sometimes, close enough to make Express the more attractive option. A lot depends on the size and weight of the package itself, but please give it a look. I’ve had situations where my clothes arrived home before I did...