You can spot a good casual summer outfit from across a garden in about two seconds. It moves when the person moves, the fabric sits away from the body in the heat, and nothing needs constant tugging back into place. A poor one looks fine standing still and then creases, rides up, or goes see through the second the sun actually comes out. The gap between those two is rarely about money, it is about a few small choices made properly.
Colour wise, the easiest things to live with are the ones that do not need thinking about every morning. Soft white, washed denim, a mid stone, olive, a dusty terracotta or a faded navy, these all sit together and against most skin tones without any real effort. Bright prints and pure white look wonderful on the first wear and then show every grass stain, every bit of sun cream, every splash from a glass of something cold, so if you love them, buy them knowing that, and maybe not in the fabric that is hardest to wash. Before you buy anything, check how it behaves when you move, not just when you stand in the mirror. Hold the fabric up to the light to see how much slip is underneath, check seams and linings on shorts and skirts, and look at where buttons or ties sit because that is usually where cheap versions let you down first, the fabric at the back of the knee going transparent in sunlight is a classic one.
For pairing, think about what is already in the wash basket rather than buying a whole new idea. A linen shirt goes over the swimsuit you already own, under a cardigan when the evening cools off, with the jeans you wear every other day. A simple cotton dress works with trainers for the school run and with sandals and a cross body bag for everything else. Nothing here should need a special occasion to justify it, that is rather the point of the whole category.
On fit, the main things worth checking are the waistband sitting where you actually want it rather than where the label suggests, and enough room through the shoulders and underarms that lifting your arms does not mean the whole top rides up. Linen and cotton both give slightly with wear, so if something feels just right in the shop it will likely loosen within a few wears, worth remembering before you size down out of habit.
Tomorrow morning I would reach for a loose cotton shirt, straight leg jeans rolled at the ankle, and the kind of flat sandals that do not mind a bit of dust.
