Great interfaces focus on the most important actions. Over time, new features and options are implemented. When something new is added, its importance is often overstated, and it screams louder than other elements, visually.
Over time, elements need to increase the visual volume to compete with all the other elements. This results in a cluttered interface that overwhelms users.
Take this action
Tone down your interface; make each element half as important visually. Find elements that can be combined for more consistency. When all the elements whisper, it becomes easy to stand out.