Pack separates that coordinate with other items in your wardrobe. Choose 2-3 colors that work well together and then take clothes only in those colors. Choose durable clothes that can be hand-washed in a pinch. Plan to dress in layers when the weather is chilly rather than bringing bulky clothes. Look for versatile items that can serve more than one purpose.
Men can get by with three pairs of trousers, four shirts, a jacket and a sweater.
Women might substitute a skirt or two for the trousers. Bring one nice outfit for evening wear. Make sure you've broken in your shoes before you leave home. Sockets are the two-pin type. Don't bother with voltage converters - they have never functioned satisfactorily for us.