My tip to make your room fresher and cleaner, WHITE—Color white makes an amazing job when we wanna or we trying to make our room look a little bit more spaceful.
One good idea to make your house look fresh is a mini terrace, there's a lot of videos where you can see how to make your own for a low cost. All you need is wood, glass beakers and plants.
If you are more into de "rustic" style you can make this cute one with wood, I think is one of the most easiest things to do. You can do it with pallets, as it is a very easy material to work with.
And the last one is putting a plant on your room, there's a lot of guides that tells you what kind of plants are perfect for your house. There is no more perfect combination than good rustic wood, a white color and a beautiful plant