在微信上添加别人为好友，你可以使用以下几种表达方式：
1. "Can I add you on WeChat？"
2. "Do you mind if I add your WeChat？"
3. "Could I have your WeChat？"
4. "Hi, I'm [Your Name], I came across your profile and thought we could connect. Can we add each other？"
5. "Hello, I'm [Your Name], we met at [Event/Place]. It was nice to meet you. Can we exchange WeChat details？"
记得在添加好友时，保持礼貌和尊重，同时根据你们之间的关系和情境选择合适的措辞。