留学生取快递时，可以采用以下几种英语表达方式：

简单明了的表达

"Hi, I'm here to pick up my package."

"Excuse me, I'm here to collect my delivery."

提供必要信息

"I have a delivery notice with me. Could you please help me find it？"

"I'm here to get my package. Could you tell me where it is？"

遇到沟通障碍时的应对

如果快递老板不会说英语，可以尝试用简单的单词和手势，或者拿出手机展示取件码或订单信息。例如：

"Package？ Yes, I have it. Where is it？"

"Please, show me where my package is. I have the delivery notice."

签名和证件

"Okay, where do I sign？"

"Do I need to show my ID？"

礼貌用语

"Thank you very much for your help."

"Sorry for any inconvenience."

通过这些表达方式，留学生可以更顺利地完成快递领取过程。建议在实际使用中，根据具体情况选择合适的表达，并保持礼貌和耐心，以便更好地与快递员沟通。