Going through the apartment with your landlord or property manager before you move in will highlight any damages or things that need repairs, so they can be addressed and fixed prior to moving in. Here is a checklist so you won't miss anything important.
Make sure that working smoke detectors and fire extinguishers are in place (Carbon monoxide detectors are less commonly found but are a good precaution). Check the building's hallways and other common areas for fire safety features, including fire alarms and sprinklers.
Check all locks and doorknobs. They should lock and not wobble. Make sure that you get keys that work for each lock. Try all windows and doors to make sure they open and close properly. Are window coverings intact? Note any missing or loose screens.
Look around the toilets and under and around every sink to make sure that nothing is damp or dripping. Make sure that faucets shut off properly and that all sink stops work. Check the tub and sinks for missing grout or tiles. Turn the shower on to test for water pressure and hot water temperature.
Test each appliance to make sure it works properly. On the stove, test each burner and the oven and broiler. Check the refrigerator and freezer closely. Make sure that they get cold, that every drawer opens and that there aren't any lingering smells. Make sure the dishwasher, washer and dryer work.
Bring a phone charger and plug it into every electrical outlet to test if they work. Turn all the wall switches off and on to make sure they work properly. This is also a good time to note anything unusual, like a light that's affected by multiple switches or if a light takes longer than expected to turn on.
Check for signs of water damage, especially on the ceilings (no one remembers to look at the ceiling). Check the walls for peeling paint or wallpaper, along with any cracks or stains.
Check closets, under sinks and elsewhere for signs of rodents or insects, such as droppings and chew marks. Make sure that the blinds and curtains open and close.
Flip every light switch on and off. Test the air conditioner on both the hot and cold settings. Listen for any strange sounds and be aware of any weird smells, which could be a sign that the filter needs to be changed. Open and close the blinds to make sure they work properly.
Run the heater and air conditioning, to make sure that both work and produce heat and cold, respectively.
Your walkthrough is the time to document any concern or problem that exists in the unit. Because this process will likely be repeated with your landlord when you move out, it's typically in your best interest to document or photograph the condition of the unit now to be able to make a comparison later.