There's a particular evening in late September, warm enough for one more dinner outside but with a breeze that tells you it won't last much longer, when you realize your patio has nothing on it that's actually doing a job. No lantern. No tray. Nowhere to put a candle that won't blow out the second someone opens the back door. That's the night you start buying outdoor accessories, usually in a panic, usually from whatever's left on the shelf in October.
Scale trips people up more than anything else out here. A side table that looked generous in a store photo turns out to hold one drink and nothing else once you're actually balancing plates and a citronella candle and someone's phone. Measure the actual surface you're working with, a step, a ledge, the arm of a chair, and buy for that, not for an imagined bigger patio you don't have. The other mistake is matching everything too perfectly, like a showroom set. Mix in one piece with a different shape or finish and the whole area looks like it belongs to a person, not a catalog. As for materials, this is where cheap shows itself fast. Powder coated metal holds up to rain and sun for years, plain painted metal flakes and rusts by the second summer. Solid teak or eucalyptus, left to silver naturally, will outlast you, while anything made of thin resin wicker cracks the first time it gets properly cold. Check the joints on anything with legs, if they're glued rather than screwed or welded, that thing is not making it through a real storm.
If you own exactly nothing for outside right now, start with lighting, not seating, not a rug. A few solar lanterns or a string of warm bulbs change how a space feels at seven in the evening more than any amount of furniture, and they're forgiving if you rent and can't drill into anything. From there, one weatherproof planter and a tray big enough to carry actual food out, rather than one drink at a time, like I did for an embarrassingly long stretch of my twenties. A balcony three floors up in a cold climate wants metal and glass that won't warp, somewhere with real humidity and bugs wants natural fiber and citronella doing double duty, and a full backyard with a grill and kids running through it wants things that survive being kicked, rained on and forgotten outside in November. Buy for the actual weather you get, not the weather in the photo.