>>5899777Unity is basically, you want all the details to be polarized toward a single main theme/idea. If it's not, it'll look chaotic. A central focal point is often a good way to achieve visual unity, but that's only unity at one layer.
For rhythm and pattern, it *could* mean that while you want a certain amount of repetition, you don't want it to be too symmetric, you want to add some variety. In music, you can go a long way with 5 notes.
OP is right: composition is key and often neglected. It's far better to have a good composition than a perfect anatomy. There are many books on composition that can help you foster your appreciation of such principles.
But nothing beats sitting around in a city, in Nature, whatever. Look for harmony.