You see lots of examples of symmetry in nature and it is an important principle generally in design. Kitchen can lend themselves to symmetry as you generally work around the key elements like the sink, range or cooker hood. Bar counters can also provide a starting point if you place them in line with units. Shelving is also used to great effect and don’t forget finishing touches like pendants - they really can inject colour and form into a scheme especially if they are placed symmetrically.