Mince ingredients into small pieces: The smaller the size of your cut, the more the ingredients will melt into each other. The texture will be smooth and uniform, coating the tongue evenly. Spices and other seasonings will be more evenly distributed.
The individual flavors will be less distinguishable, but your dish will have a succulent flavor-base that highlights other ingredients and flavors in the dish. These dishes tend to feel more refined and delicate.
Chop ingredients into larger pieces: Larger pieces will retain more of their individual flavor in the final dish. Instead of melting into a single flavor, you'll taste several distinct flavors and textures in every bite.
You can also mince some ingredients while leaving other ingredients in larger pieces. The minced ingredients will become a background flavor while the larger ingredients are showcased. For instance, if you want to make sure your highly-prized oyster mushrooms take center stage in your risotto, finely mince the ingredients for the soffrito and leave your mushrooms in whole pieces.
Just remember that the smaller the ingredient, the more quickly it will cook. To avoid overcooking, you can cook larger ingredients separately and then add them in at the end.
Give it a try next time you make a familiar recipe!