如果你想讨论你朋友的衣服，你可以说：

What do you think of my friend's outfit?
Do you pke my friend's outfit?
What's your opinion on my friend's outfit?
I'm not sure if my friend's outfit looks good. What do you think?

你也可以更具体地描述你朋友穿的衣服，然后问对方的意见，例如：

My friend is wearing a blue sweater and jeans. Do you think it looks good on them?
My friend has on a black dress and red heels. What do you think of the combination?

总的来说，你可以用各种方式来讨论你朋友的衣服，重要的是要让对方知道你在询问他们的意见。