Dry clean, and less often than you'd expect. A tailored jacket carries interfacing, canvassing and shoulder structure that solvents and pressing gradually flatten, so once or twice a season is plenty for most wearers. Between cleans, a soft clothes brush after each wear lifts dust and keeps the surface fresh, and small marks come out with a barely damp cloth blotted rather than rubbed.
Rest the garment for a day between wears so the cloth recovers. Hang the jacket on a broad wooden or shaped hanger — never wire, which cuts into the shoulder line — with the buttons undone and room on either side.
Trousers want hanging from the hem or the waistband on a clamp hanger, which keeps the crease sharp and lets the leg drop straight. Folding over a bar works too, as long as the fold sits on the existing crease rather than across it. Trousers take the wear in a suit, so they'll need cleaning more often than the jacket — but clean both together when you can, since dry cleaning shifts colour very slightly over time and separating them eventually shows.
Steam rather than iron to drop creases. If you do iron, use a low heat with a pressing cloth between the iron and the cloth, and never press directly onto lapels, pockets or the shoulder — those areas are shaped in construction and a hot iron flattens them permanently. Store in a breathable garment bag rather than plastic, and always clean tailoring before putting it away for the season, since marks that look invisible will set over the summer.
