- Arrive a bit early
- USCIS building may have multiple entrances and lines. Make sure to join the right line
- If you can avoid wearing metal and boots / shoes with thick soles, baggy clothes l, belts, watches etc don't wear it. Because you'll be going through metal detector. The less stuff you wear the better
- Don't bring laptops and backpacks if you can
- Be ready to spend 1-4 hours at the building in case of same day ceremony
- Bring bonafide marriage evidence for N-400 if you filed under 3 year rule
- Bring all valid and expired passports
- Bring all green cards (including expired), EADs, Advance Paroles and other ID cards issued by USCIS
- Do not talk too much, let officer do the job
- Give short, direct, confident answers. If possible, yes or no. If you don't know something, say you don't know.
- Remember travel dates, key relationship dates, addresses you lived and worked at. Remember key info about each other.
Good luck!