Most of you probably know the possibility of moving to a tile by clicking on it. Many MMORPGs do offer this way of moving your character, but also games like AgeOfEmpires.
So here´s my suggestion.
Each tile/NPC can be clicked via mouse. The player will walk automatically to the tile/NPC and interact with it. For PC users this method might seem not too necessary, but think about porting the game to android. A virtual D-Pad would take a lot of place and might be annoying. Tapping a tile will make the game more comfortable and better for portable devices.
Greetings, Matzeus