Formal:
* 您好吗？ (nǐ hǎo ma?) - This is the most polite and formal way to ask. It literally translates to "Are you well?"
* 贵庚？（guì gēng?） - This is a very formal way to ask someone's age, which can be interpreted as "How are you?" in some situations.
Informal:
* 你好吗？ (nǐ hǎo ma?) - This is a more casual way to ask, similar to the formal version.
* 怎么样？ (zěn me yàng?) - This is a very common way to ask "how are you" in informal settings. It literally translates to "How is it?"
* 最近怎么样？ (zuì jìn zěn me yàng?) - This means "How are things going lately?" and is a more personal way to ask how someone is doing.
More colloquial:
* 还好吗？ (hái hǎo ma?) - This is a more casual way to ask "Are you okay?"
* 怎么样啊？ (zěn me yàng a?) - This is a very casual way to ask "How are you?" and is often used with friends or family.
The best way to choose the right phrase depends on the situation. If you're speaking to someone you don't know well or in a formal setting, use the more formal options. If you're speaking to a friend or family member, you can use a more casual phrase.
It's also important to note that Chinese culture is very hierarchical. It's important to use the appropriate level of formality depending on your relationship with the other person.