Nothing here yet.
Summer work casual has a reputation for being the easy category, the one where you just grab a polo and some chinos and call it done. I don't think it's that simple, and I've got the drawer of slightly-too-thin linen shirts to prove it. Done well it's the most comfortable I am all year at a desk. Done badly it looks like you gave up on dressing for work entirely.
The main thing to avoid is treating it like proper weekend kit with a few compromises bolted on. Shorts, however smart the fabric, don't belong in this category once you're near clients or a meeting room, and the same goes for anything with a heavy branded logo across the chest, it reads as leisurewear whatever the price tag said. Trainers can work, but not the chunky trail ones you'd wear to walk the dog, and definitely not alongside tailored trousers, the proportions just fight each other. Keep the smart and the casual elements in balance rather than letting one half drag the other down.
How this stuff ages matters more in summer than any other season, because you're washing it constantly and wearing it against bare skin in heat. Linen and linen blends soften properly after four or five washes and start to drape better, but they'll crease the moment you sit down, and no amount of ironing fixes that permanently, you have to make peace with it. Lighter cottons wear thin at the elbows and collar faster than you'd expect if you're doing a commute in them twice a day, so don't buy the cheapest option expecting it to last a full season of actual wear. A cool wash and a hanger rather than a fold does more for shape than any fabric conditioner claim on the bottle.
On colour, I've learned to stay in the mid range. Pale blue, stone, sage, a soft grey, these all survive sweat marks and sun fading better than anything stark white or properly dark. White shows every coffee drip and underarm mark by lunchtime, and navy or black absorb heat in a way that makes an already warm office feel worse, plus they fade unevenly in the wash over a summer of wear. Stick to those forgiving middle shades and you'll get more actual use out of the piece before it starts looking tired.
Where this all falls apart is formality. If your office still expects a jacket and tie, or you've got client meetings most days, summer casual pieces are a supporting act at best, not the whole outfit, and no amount of good linen changes that.
Nothing here yet.