Here is an something similar to what I am wearing today! I am wearing coral shorts though, since it is really warm where I am at!
(this is not my picture!) Putting your hair up in a bun is an easy way to look put together without looking like you tried too hard! Also, we all know that colored jeans/shorts are really in for this spring and summer! Adding sunglasses and a watch are two more ways to just add a little something while keeping it simple. Lastly, denim shirts are REALLY popular right now and there should definitely be at least one hanging in your closet!