A blue chambray long sleeve shirt and olive cargo pants are amazing menswear essentials that will integrate nicely within your casual wardrobe. If you wish to effortlessly perk up your getup with a pair of shoes, why not enter a pair of brown suede desert boots into the equation? When leaves change color and fall is in full swing, you'll love this combination as your favorite for summer-to-fall weather. And if we're talking casual fashion for 30-year-old guys, this look is perfect.