Once you have either six drake scales or one dragon scale, take them to Wade in Denerim. He will make them into armor for you. The first set of three drake scales will be made into drakeskin leather armor. Pay him the 10G for that set, and pay the 20 for the second set of improved drakeskin leather. Then the drake scale armor, which you have a choice of three types, all being heavy to massive, will be better quality. Though a word of warning, once Wade has made all three sets of armor, you will not be welcome in the store again, so purchase anything else sold there first.