Cheapest way to ship from Canada?

Hello all.
I want to start swapping, so I started to look at shipping prices with Canada Post, and their options are pretty pricey. To all the Canadian swappers, what do you use to ship internationally/ nationally?

I wouldn't mind some tips as well, since that's one of the major reasons why I don't swap at all.

If you can cross the border into the states, and it is not too far, use the usps.
But please put up the prices that you have for shipping letters from canada.
Perhaps putting button sized coins in between real buttons could help ship as sewing button samples, gift.
A letter with one coin inside a cardboard flip, wrapped with several sheets of printed paper might work.
Good luck.