It’s a mix of general autistic things, and things I personally do as a cis-autistic. Autism presents very broadly so you’ll have to navigate what works for you! Feel free to suggest more in the comments.

• Develop a special interest and learn a lot about it! Tell everyone about it!
• Use obscurer words in your every day vocab. Examples; greetings, mayhaps, overmorrow, variegate, betwixt, whence.
• Stim! Examples; echolalia, repetitive movements, stim toys, music.
• Interpret things literally, especially when it’s coming from a stranger.
• Plan everything!
• Develop a more monotonous voice and/or flat/blunted affect.
• Accentuate your quirks!

Other common traits of autism are sensory/processing issues, meltdowns, and social clashing.