As a designer, I'm constantly learning about my design preferences, and they are always changing and being fine tuned! One thing I know is that I really prefer balance over symmetry. Balance is when two or more items are the same height or size. Take a look at the picture on the right-the olive tree and the lamp or balanced-they are of the same height.
Symmetry is when things are the same exact pieces-where it matches on both sides. If for instance the picture had two olive trees or two lamps, then that would be symmetrical.
I like design to look like it wasn't' too hard to achieve. I think that's why I prefer balance over symmetry. It just looks like it wasn't too difficult or fussy, but it still makes sense to the eye. Balance is very comforting, where symmetry can be a bit overbearing or stiff.