After "as," you can put a few different things depending on the context:

Adjective or Adverb Clause: You can follow "as" with an adjective or an adverb clause to provide additional information about the action or situation. For example:

He sang as beautifully as an angel.

She worked diligently as if her life depended on it.

Prepositional Phrase: "As" can be followed by a prepositional phrase to show the role, manner, or condition in which something is done. For example:

She treated the patients as a caring nurse.

He carried himself with confidence as a seasoned professional.

Comparison: "As" is often used in comparisons to show similarities between two things. You can follow it with an adjective, adverb, or phrase. For example:

He is as tall as his older brother.

She drives as carefully as a professional racer.

Clause of Reason or Cause: "As" can introduce a clause that explains the reason or cause behind a certain action. For example:

As I was feeling unwell, I decided to stay home.

Direct Quotation: In some cases, "as" can introduce a direct quotation. For example:

She said, "As they say, 'Practice makes perfect.'"

Keep in mind that the choice of what to put after "as" depends on the intended meaning and context of your sentence.