Do not have have your cell phone out on your desk or checking texts or messages during office hours.
No Facebook or social media- unless on breaks and own your own personal device.
If there is a lunch make sure to clean up after yourself. You are not at home and no one person in the office cleans up after everyone. Pitch in.
Be social. If everyone goes to the lunchroom to eat, go there as well. The work day goes much faster when you get to know your coworkers and get to know them on a personal level. Try not to text or type when talking to your coworkers. They deserve your undivided attention and you may need their help down the road or to be a reference.