Some guys on here say they have had good results with flyers/door hangers and by leads from their websites.
As far as the direct/walk up approach, it could work or it could turn people off. Some people just hate being put on the spot. But you really you get that with any kind of advertising. Some people will look at a door hanger and others will throw it straight in the trash without a glimpse.
Good luck and welcome to the site!