My brother and I have always stacked our dishes to make it easier for our server when he/she came around. They always appreciated it, just like our saying Thank You to our server when he/she brought something or did something (like refilling your tea or water glass), it made them feel like you really appreciated the work/effort to go the extra little mile (even knowing that was part of the service/job). And I always leave a good tip for good service. My parents are the same way. They consider it common courtesy to be nice to your wait staff.