Sparkly jewelry will add an "icicle" effect to your outfit.
String icicle lights around the edge of the room.
Pipe royal icing onto parchment in the shape of an icicle.
Then use a dab of icing to glue the icicle onto the house.
Simple icicle lights lining the room with garland around doorways, and holiday bows around chair backs can create a festive mood without going over the top.