Ok. you need more effects for the sigs, a lot of them look like you just put a picture on a background. you have to work on making to focus clear so it draws the attention of the viewer. You also need to blend your main focus into the background. At last, pick colors that go with the render (main image) For example, the one on the top left, the orange background does not fit the render. Keep working on it though, you will get better.