Have you noticed that most wall art today is displayed in multiples? Say, three of one version, hung in a row. It's a fresh look. Possibly remove some of the wall hangings and put them aside for now. Clean walls with the multiples is right now! Your room will look updated and with it. I will go look at my own now, it's a difficult project.
We have all, at this stage, collected some fabulous photos from our families throughout the years. To display these, choose one wall, (black and whites are fabulous) and stick with the same frame type. For instance, black frames all around. Or silver, or whatever you choose, just make it cohesive and in one spot, not scattered.