To deck someone or something out (in something)

To deck someone or something out (in something) - to decorate someone or something with something.

Example - "Sally decked all her children out for the party"
                  "They were all decked out in their best clothes"
                   "Tom decked the room out with garlands of flowers"

Image - http://www.quotehd.com/imagequotes/authors30/tmb/cecil-flowe-quote-well-get-him-decked-out-in-orange.jpg