I put a low teak bench on my balcony, the kind with clean square legs and no fuss, and it was the first time the space felt like a room instead of a place I stored a bike. Nothing matched, nothing coordinated, it just sat there looking like it belonged outside and like it belonged to me. That's the whole appeal of modern outdoor furniture, it's architectural enough to hold its own against a plain concrete patio or a chaotic little garden full of plants I've overcommitted to.
If you've got nothing out there yet, start with one seat that can take weather without sulking about it, a single lounge chair or a two seat bench in something like teak, eucalyptus or powder coated aluminum. Skip the all in one bundled sets at first. You end up with four chairs you didn't choose individually and a side table nobody needed. One good piece earns its spot, then you build around it once you know how you actually use the space.
Measuring outdoor furniture is not like measuring a sofa, because you're also fighting doors, slopes and the fact that your tape measure lies to you in direct sunlight. Walk the actual path you'd take carrying a drink and a plate, elbows out, and make sure a chair doesn't block it. Leave at least three feet behind any seat that needs to push back. And measure your gate or stairwell before you fall in love with a sculptural chunky piece that will not fit through either, I did this once with a concrete look planter stand, it lives in my hallway now, it is not a planter stand anymore, it is a coat rack.
Where it goes wrong is mixing too many eras in one small space, a sleek low slung metal set next to a wicker rocker and a gnome just reads as confused, not collected. It also struggles on busy patterned brick or tile, the clean lines get swallowed. Give it a plain surface, concrete, decking, gravel, and let the furniture be the shape in the scene.
What's kept me loyal to this style is how it survives actual outdoor life, not showroom life. A year of rain, bird mess, a dropped lasagna dish and one move across town later, mine still looks the way it looked on day one, just with slightly better stories. Cushion covers wash, frames wipe down, nothing warped or faded in a way that bothered me.
Would I still want to look at this piece after a winter of neglect and one too many storms?