I think it would be an excellent idea for you to write an essay about your room. A French writer named Xavier de Maistre wrote an essay titled "Voyage autour de ma chambre" (A Voyage Around My Room) while confined under house arrest in the eighteenth century. I wish I could tell you more about it, but I have to confess that I liked the idea very much but never got around to reading the work.
You can't write about anything without writing about yourself. There is the object and then there is the subject (you) looking at the object and having thoughts, feelings, and memories about it. You can focus on a single object and have a great deal to say about it if you give it some thought.
A woman once told Henry James that she wanted to write about a certain subject but was afraid it wasn't sufficiently important. He told her: "Write about it and you will make it important."
If your room is important to you, you can make it important to a reader. I am reminded of the term paper Holden Caulfield wrote about his brother's baseball glove in The Catcher in the Rye. You can not only write about your room, but you can stop anywhere while voyaging on a clockwise or counter-wise journey and tell about one particular object. (Are you going to journey clockwise or counter-clockwise?)
For example, I have a wall calendar above my desk which features reproductions of paintings by Claude Monet. I love Monet's Impressionist paintings and could write a great deal about just the one for February, which shows an old sailing ship with storm-tattered sails. I could write about the pictures I haven't seen yet because I only turn the pages once a month, and I could write about my daughter who gave me the calendar for my birthday because I sort of hinted that I like Monet.
I think writing about your room would be a great opportunity, rather than having to write about some assigned topic that could be like pulling teeth.
Best of luck!
It is really up to you, but in my opinion, there must be more interesting things to write about than your room. However, if the assignment is just an essay that seeks to be descriptive, then any topic would be fine. In light of this, let me give you some suggestions for writing this essay.
No matter what topic you choose, you can make things interesting as long as you give details and view something from a new perspective. This will not be easy to do, but if you think about it, then you will be able to be creative. I suggest that you make an outline before you start writing.
Another suggestion is to give personal stories of why you like something in your room. For example, you might want to write about something in your room that has sentimental value or some special importance. If you tell the reader the reason for it, it can create a bond between you and the reader.
Descriptive essay is good if you want to describe about your room, but first you have to ask yourself why and how will your essay attract the readers. Therefore you have to be more specific and not just write everything that you want. For example, instead of telling the readers how you arrange the stuff in your room it is better if you tell them why you arrange it that way, perhaps to help you focus more when you study(just an example). It is nice to include personal feeling in your essay so that the readers will not get bored.