I AM Canadian, and if you see my Heat I've done plenty here in terms of FS/T.
1. Please ship only USPS to Canadians and NOT UPS. They charge HUGE fees ($40) on top of what the item costs. 95% of the time through USPS, no duties come through.
2. Mark the item as a gift. That won't help much, but any little bit helps.
3. Try to put a low declared value, but of course what it's worth. If the item was bought off FS/T for $25, puttint $20 wouldn't hurt. Obviously you can't list a laptop under $20, but just be reasonable and not put down the MSRP.