There's a particular stretch between the last warm weekend and the first party invitation when satin trousers suddenly make sense. Too mild for proper evening wool, too dressed up for denim, and you want something that photographs better than it feels like effort.
If you've never owned a pair, start with a straight or slightly wide leg rather than anything tapered or cropped. Satin clings to detail in a way that's unforgiving round the ankle, and a looser leg disguises the fact that this fabric shows every line of what's underneath it, including seams you forgot you were wearing. The cheap version usually gives itself away on the hanger, a sort of plasticky shine that looks like it's lit from within under any artificial light, and it creases in a way that doesn't drop out, so you end up looking like you slept in a bin bag with a waistband. A better weight has a duller, heavier sheen, moves when you walk rather than flaring with static, and the creases fall out by the time you've hung it in a steamy bathroom for twenty minutes. Colour matters more here than in almost any other trouser. Black is the easiest entry point because it behaves itself and hides the inevitable shine variations that happen when you sit down for three hours. After that, a deep bottle green or a warm bronze earn their place far more readily than anything pastel, which tends to show every pull and crease and makes the cheap fabric look cheaper still. Fit is where most people go wrong twice. Satin has almost no structure of its own, so it needs the hips and seat to be right rather than relying on the fabric to skim and forgive the way a ponte or a crepe might. Too big and you get pooling at the thigh that looks like you're wearing someone else's trousers. Too small and every seam strains and catches the light, which is the opposite of what you want from something this shiny. Go up rather than down if you're between sizes, and check the rise sitting down, not just standing, because satin shows a gape at the waistband that cotton would never confess to.
These earn their keep from early autumn through to the point in January when everyone's sick of sequins, worn for dinners, work parties, anything with a seating plan rather than a dance floor.
Tomorrow morning I'd put mine with a plain fine knit jumper and flat boots, nothing else trying to shine.