Linen trousers are the warm weather trouser that nothing else quite replaces because the breathability and the natural weight of linen in summer heat is genuinely superior to cotton alternatives and dramatically superior to anything synthetic. They do crease and accepting this rather than fighting it is the right approach because trying to keep linen perfectly pressed is a losing battle that ends in frustration. The relaxed quality that comes with linen including the natural creasing is part of what makes it feel so appropriate for summer. A straight or slightly wide cut in stone natural or white with a simple short sleeve shirt or a lightweight tee and loafers or sandals is the summer casual look that works in the south of France and works just as well in the south of England on the two or three days a year that actually justify it.