我开了一个服装公司，制作衣装和裤装。另外，我的衣柜里有很多衣裳。

服装: Usually seen in business, like clothing(服装) shop（店）。 衣裳：Usually seen in oral language, like what cloth are u gonna wear today? 衣装：Usually seen in written language, such as she's wearing a gorgeous dress.

服装的概念比较广，全身上下所有的衣服鞋帽都可以用服装表示，但一般多指衣服。 衣裳则等同于衣服，概念比服装要小一些，多指上半身服饰。 衣装更像是一个词组，相当于“衣服的装扮”，常用搭配“人靠衣装”，意思是“人要靠衣服来装扮自己才能更漂亮”。

Hi Kobold, it will depends on the context of your sentence, but 服裝 is more common. Perhaps you can provide more details.