Effortlessly blurring the line between cool and laid-back, this pairing of a brown plaid flannel long sleeve shirt and olive cargo pants will likely become your go-to. Got bored with this ensemble? Enter dark brown leather casual boots to spice things up. And if you're looking for a kick-ass getup that will take you from winter to spring, you found it. This getup demonstrates that as a gent in his 30s, you have a vast array of style options.