Must have: Denim Shirt
The denim shirt should be thin and of a distinctly different color than the jeans. Ideally suited to each other objects of the same color, varying in tone.
Also will look well with a light top dark bottom and vice versa.
Choose light denim for your shirt and make sure it fits you well. No bagging, no major bunching if you are tucking it in. You may wear it tucked or untucked.