Question:

My room is 3 meters by 3.5 meters. I already have a large desk taking up the majority of my room, a single bed and dresser/vanity. Are there any possible smaller changes I can make while having a good effect?

Answer:

Since I do not know what your furniture looks like or what your room layout is, I have made a small project for you. It is for a 3 m x 3.5 m room and it has the basic furniture you mentioned.

I hope you get some inspiration from it.

Place a big floor lamp by the bed side, for a great visual impact. Replace the bedside table with a smart looking shelf.

You may also consider purchasing a sofa-bed. 

Arrange the desk and the dresser so that they look balanced against the walls. You can install a hanging ceiling lamp over the desk. A shelf might help with storing the books.

Match the tripod lamp with a small dresser lamp. Arrange the bed nicely and I think you are set for a stylish and functional small room. 

Cheers.