Man OP, why would you do this to yourself? It's like you picked, for each item, the most ubiquitous thing possible, then put them all together and called it an outfit.
The shirt is kind of a loss all around; it's the same short-sleeved plaid shirt everyone in the world is wearing this spring, but it's in really fall/wintery colors that don't mesh with the rest of the outfit. The cargo/cloth belt combo is standard college fratwear (although the belt looks salvageable if not particularly good), and the shoes are tacky and boring.
If you like the shirt, why not try a shirt in a more spring-colored plaid? You'll still be wearing that style of shirt, but it will match everything else. Trousers could be something interesting like corduroy or linen, just as long as they're fitted like the shirt. Shoes and belt would probably look best in light brown leather, but you could wear sneakers (white canvas is your friend for spring/summer).