Bring a phone charger, a bucket of water and this list. Test every electrical point with the charger. Run water in every tap and shower for two full minutes and watch the floor traps drain. Pour the bucket across the veranda and bathroom floors to confirm the slope carries water to the drain, not the doorway.
Open and close every door and window twice; check that locks seat smoothly and window channels are clean. Inspect tile lines under raking light for lippage and hollow sounds. Check the kitchen platform edge, the sink trap, and the exhaust cutout. In the bathrooms, confirm hot-water lines where promised.
Then move to paperwork: the completion certificate, utility meter numbers in your name or clearly transferable, parking allocation in writing, and the society formation documents. A professional developer will walk this list with you and put every snag on paper with a date. That, more than marble in the lobby, tells you who you bought from.