Knock on doors. :-)

so, i found out that Canadian laws discourage pre-foreclosure leads for public. i just lost my marketing idea.

as a beginner, i am thinking of going to knock on doors. (find sellers) anyone have good/ok experience in doing that? what are some things that i need to watch out for, or look for, before knocking on a house?

any feed back appreciated.
an apprentice warlord