Summer or winter, the denim jacket is a MUST have! It can act as the main focus of your look or can bring out the rest of your look. Brands are starting to notice the trend and thus will start stocking these more in different shapes and sizes so I advise you look for the perfect one before you make a decision.
With my look, I went for darker colors to try bring out the jacket as much as possible but you can decide you want the jacket to blend in, in which case you could pair it with a denim shirt or a white shirt/t-shirt to play with contrast and texture!
(Denim jacket from Wrangler)