Children (especially girls) love playing decorating games, so I use Baby Room Maker and Pink Princess Room to help them learn how to describe a room and have fun at the same time. First, I decorate a room and describe it myself - the child listens/repeats. Then the pupil tries to decorate the room and describe it with my help. You can take several different rooms so it doesn't become boring too fast. As a hometask, I ask the pupil to make a room (online) at home and describe it in written form (we practise that in class, too). At the next lesson s/he reads the description to me and I make a room following it. The pupil says if it's the same then. I use such online games not only to practise vocabulary (furniture and prepositions), but also the pronouns it/they + is/are and the usage of there is/are as well as articles (a/an/the).
You'll find many more decorating games here. Have fun!
Here is a worksheet to practise writing.