The more detailed the shirt, the more simple the bottoms should be. Balance is very important. Wear the sleeve length according to the proportion of your arms. Heavy arms look better in cap, 3/4, or long. Skinning arms look best in above the elbow length.
Classic looks, understated. Subtle color combinations. Simple and refined. The brighter the colors and the business of the design, the more simple the lines of the clothing should be. Staying subtle is the key.