Formal:
* ཁྱེད་ལ་དྲན་པས་སེམས་ཁྲལ་ཆེན་པོ་བྱུང་། (khyed la dran pas sems khral chen po byung): This literally translates to "I am very worried because I remember you." It is a very formal and respectful way to express missing someone.
Informal:
* ཁྱེད་ལ་དྲན་པས་སེམས་སྐྱོ་པོ་འདུག (khyed la dran pas sems khyo po dug): This translates to "I am a little sad because I remember you." It is a more informal way to say "I miss you."
* ཁྱེད་ལ་དྲན་པས་འགྲོ་འདུག (khyed la dran pas 'gro dug): This literally translates to "I am going because I remember you." It's a playful and more casual way to say "I miss you."
Other options:
* ཁྱེད་རང་ལ་དྲན་པས་སེམས་ནད་འདུག (khyed rang la dran pas sems nad dug): This translates to "I am sick at heart because I remember you." It is a poetic and expressive way to say "I miss you."
* ཁྱེད་ལ་དྲན་པས་སེམས་བསྐྱེད་འདུག (khyed la dran pas sems bskyed dug): This translates to "I am thinking of you." It is a more subtle and gentle way to express missing someone.
Ultimately, the best way to say "I miss you" in Tibetan depends on the specific context and your relationship with the person you are talking to.