Best way to ship small value items--US to Canada??

I just did a search on this topic on A'gon, & did get quite a bit of info. Also, I have mailed a couple of CD's (USPO) to Canada with apparently no problem.

My current dilema: I sold a small $25 item to someone in Toronto (from US). I tried to ship it UPS, & spent about 1 1/2 hours on their website trying to decipher all the customs forms, which I think would need a really good lawyer to figure out. Finally, there was a place to click something (???) where I wouldn't have to send all the forms with the item, just sign something on the pack of the UPS label. Of course, the UPS guy later refused to take the box, saying I had to have "all 3 forms attached or it would just be totally stuck in Customs".

So, I voided the UPS shipment, now I'm thinking of sending USPS.
If I'm using their website correctly, it would cost only $2.35 to send a small 8 oz. box to Canada via "Airmail Letter Post ". Or, I might (not sure) be able to fit it into a Global Priority Mail - Flat-rate Envelope (large) for $7. Of course neither would have insurance or tracking. And I charged less than $10 for shipping so Global Express Mail at $15.50 is out.

Any advice? I'm thinking use the Airmail Post & take my chances. BTW, as I recall, the USPS only requires a brief 1 page Customs Form, not 3 pages like UPS. Thanks in advance for any advice!