Standing wardrobes are used to ship clothes that hang on closet rails. Although quite cumbersome to tape up, they are taped just like any other box except you add some extra reinforcement by taping twice.
Depending on the length of the garments you are hanging in the wardrobe, you can put extra stuff on the bottom such as pillows, comforters, shoes and boots, umbrella’s etc.
Hang the clothes on the rail until the rail capacity is reached. If you have a lot of suits and coats, try and disperse them between a few wardrobes and mix them with lighter items such as dresses so as to distribute the load evenly. Hanging nothing but suits and coats in one wardrobe can cause the load on the rail to collapse the sides of the wardrobe, rendering it useless.
When you have packed the wardrobe fold over the flaps and tape it up. Mark the contents and room destination on the outside of the wardrobe so as you don’t have to move it more than once at the destination.