Cats explore with their paws and their mouths. Most of what hurts them at home is ordinary stuff in ordinary places. A lily on the windowsill. A hair tie under the sofa. A screen that pops out of its track. Walk each room before the carrier opens and fix the obvious things at cat height.
The living room
Start with cords. Charger cables, lamp wires, blind pulls, and curtain ties are all chewable and stranglable. Tape cords to the baseboard, run them through cable sleeves, and cut the loops out of blind cords. A neighbour's kitten got tangled in a blind cord and didn't make it. Cut the loops the day you adopt.
Anchor anything that can topple. Bookshelves, TVs, floor lamps. A cat will climb whatever it can, and a falling bookcase is fatal. Wall straps cost a few dollars.
Look under the sofa and behind cushions for swallowables: hair ties, rubber bands, coins, push pins, small toy parts. String, ribbon, dental floss, and tinsel are the worst. They cause linear foreign body obstructions, which usually need surgery.
The kitchen
Counters are not off-limits to cats. Assume they will be up there.
Keep cleaning chemicals, dishwasher pods, and pest bait inside a closed cabinet. Use a child-proof latch if you can. Bleach, ammonia, and concentrated essential oils are toxic.
Watch the stove. Cats jump onto warm hobs minutes after the heat is off and burn their paws. A flat induction top cools faster but still holds heat. Cover open flames when cooking.
Foods to keep sealed away: onions, garlic, chives, grapes, raisins, chocolate, raw dough, alcohol, and anything sweetened with xylitol. All toxic to cats in small amounts.
The bathroom
Close the toilet lid. Kittens drown in them. The bowl water often contains cleaner residue too.
Medications go in a closed cabinet, not on the counter. Paracetamol (acetaminophen) is lethal to cats in a single tablet. Ibuprofen, antidepressants, and ADHD medication are also serious. Pick up any pill that hits the floor before the cat does.
Hair ties, dental floss, cotton buds, razor blades. Drawer, not counter.
The bedroom and laundry
Check the washing machine and dryer before every cycle. Cats climb into warm drums and sleep. A quick look takes two seconds and prevents the worst phone call you'll ever make. I've done thousands of loads, and I still check every single time.
Keep wardrobe and drawer doors shut. Cats squeeze into spaces you didn't know existed and get stuck.
Under the bed: sewing pins, earrings, small batteries, silica gel packets.
Windows and balconies
Cats fall. They don't always land on their feet, and from above the second floor they often don't survive. Fit secure mesh on every window that opens and on any balcony the cat can reach. Magnetic flyscreens pop out under a cat's weight. Use a fitted frame.
Don't rely on a "they'll figure it out" closed window. A cat chasing a bird will hit glass at full speed, and a screen on a track will give way.
Plants
Lilies are the headline. True lilies (Lilium and Hemerocallis) cause acute kidney failure from even a lick of pollen or a sip of vase water. Remove them entirely. Don't try to relocate them, the cat will find them.
Also remove or move out of reach: sago palm, aloe, jade, snake plant, pothos, philodendron, ivy, dieffenbachia, dracaena, amaryllis, tulips, daffodils, azalea, oleander, and asparagus fern. The ASPCA keeps a searchable list. Check anything you're not sure about.
Safe alternatives that look nice: spider plant, Boston fern, parlour palm, calathea, money tree, African violet, cat grass.
A final pass
Get on the floor and look up. You'll see things from cat-eye level that you missed standing. A dangling cord. A gap behind the fridge. A hole in the skirting board. The top of a cabinet that's a clear leap from the bookshelf. Block what you can, accept that the cat will find the rest, and check back in a week. (You will absolutely miss something. I did. They find it within 48 hours.)