A windowed door with extensive glazing might seem like a real challenge, but a two-part hanger consisting of an outside knob held against the glass by a strong magnet placed on the inside, such as the Hanger Knob from Lee Valley, will hold up to three pounds (1.5 kg), so you can simply suspend the wreath from the knob with ribbon.
If you've got a wooden door, hammer a flat-headed metal tack into the top edge (check that the door still opens and closes as usual). As you tap in the tack, punch through one end of a length of wide, festive ribbon (fold the end over to avoid a tear), then tie it in a bow around your wreath.
Excerpted from Canadian Living The Complete Christmas Book by the editors of Canadian Living Magazine Copyright © 2007 by the editors of Canadian Living Magazine. Excerpted by permission of Transcontinental Books, a division of Random House of Canada Limited. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.