Brush and air after every wear. Tailored wool — the overcoat and the dress trousers — is refreshed far more by a soft clothes brush and a night on a good hanger than by any wash. Brushing lifts dust and grit before it dulls the cloth, and airing lets the wool recover its loft and shed the day's creases and smells.
Steam, don't press flat. A handheld steamer, or a warm iron through a damp cloth, relaxes wrinkles and revives the drape without crushing the weave or leaving a shine. Hold the steam a little off the surface, let the piece dry on the hanger, and the cloth falls back into shape on its own.
Dry clean sparingly — only when actually soiled. Solvent is hard on wool and its finish, so clean at most once or twice a season, ideally once at the end of winter before storing. Between times, sponge spots with a barely-damp cloth and let the garment air rather than reaching for the cleaner.
Hang broad, store covered. Use a wide, shaped hanger so the shoulders keep their line, give the coat and trousers room to breathe on the rail, and store them under a cotton garment bag — never sealed plastic. Empty the pockets so they don't bag out, and check the folds for moths before any long spell in the wardrobe.