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. If you can find battery-powered appliances, make sure they run on AA batteries which are readily available in Germany and Austria. You should leave some room in them, then squeeze the air out before you put the lid on. This will keep the contents from leaking out in flight. Pack these in a waterproof bag.