My eldest son decided he wanted to be Harry Potter (we're reading the books to him at bedtime) so off we went to our local Value Village where we purchased a Gryffindor robe, glasses, wand and broomstick. My younger son ended up selecting a Slytherin robe for his costume but he insisted on having glasses just like his brother. The result was a very frustrated little boy because everyone kept commenting on the two cute Harry Potters. "I'm Draco Malfoy" he would insist. We finally determined an explanation for the glasses - he was Draco Malfoy but drank some polyjuice potion to turn into Harry Potter and he was only part way through the transformation.
Regardless of the costume confusion, both boys had a lot of fun running around casting "expelliarmus" and "riddikulus" spells at everything that moved.
The final step was journalling but you really can't make it out well in the pictures. I used a fine black pen and wrote in many of the blank areas of the pages but the fineness of the ink makes the words blend into the background pattern ... not sure if I like that or not. Hmmm.