Pretty much what Obscura said. When I need to design a game costume for a... paladin, for example, I go through and look at several games that I know have that class and look at what makes a paladin, take elements that I like from 10 different costumes and go from there. It's difficult to come up with something totally unique. I'd look up middle eastern/north african costumes, or of course, you could always go the cowboy route xD
What I can tell you is that for a desert place, that fabric is much, much too heavy. You'd keep your body covered for sun protection, yes, but often people choose thin fabrics of a light color because it reflects light and therefore heat. The fabric needs to be breathable. The guy also needs some head protection. With his blonde hair, he'd probably get sunburn on his scalp depending on how strong the sun is. Even people with dark hair can get sunburn where their hair parts. Very painful, trust me :p I think the exception to the rule is at night, though (Or the Gobi desert in China/Mongolia where it is really cold most of the time). Moisture in the air prevents drastic temperature change because of water's high specific heat. Deserts don't have that so as soon as night hits, the air rapidly cools down. As a result, you often have high winds. Might be a little too much information, but I've always believed that an artist needs to fully understand something before they can properly draw it.
Oh, and awesome job painting his torso. I love the muscle structure