写明信片时，以下是一些常用的英语表达方式：

1. 打招呼：Dear [姓名] (尊称),Hello [姓名] (亲昵的打招呼),Hi [姓名] (友好的打招呼),

2. 介绍自己：I hope this postcard finds you well. (希望你一切都好。

)I am writing to you from [地点] (我从[地点]给你写信。)I am having a great time here in [地点] (我在[地点]过得很愉快。)

3. 描述旅行/体验：The weather here is fantastic. (这里的天气非常好。)The scenery is breathtaking. (景色令人惊叹。)I've been exploring all the famous landmarks. (我一直在探索所有著名的地标。)I've tried the local cuisine and it's amazing. (我尝试了当地的美食，非常棒。)

4. 询问对方的近况：How are you? (你好吗？)How are things going with you? (你过得如何？)I hope everything is going well for you. (希望你一切都好。)

5. 邀请对方来访：I would love to have you visit me here sometime. (希望你能有机会来这里玩。)You should plan a trip to [地点] sometime. (你应该计划一次到[地点]的旅行。)Let me know if you ever decide to visit. (如果你决定来访，请告诉我。)

6. 结尾与祝福：Take care and keep in touch. (注意身体，保持联系。)Wishing you all the best. (祝你一切顺利。)Sending you warm wishes. (寄去我的温暖祝福。)希望这些表达方式能帮到你写明信片时选择合适的词句。祝你写信愉快！