Portable closets are easily assembled, but the exact method will vary, especially depending on the components of the closet, like shelves and other storage spaces within it. You should always check the included directions with the closet you get.
Assembly
Most portable closets start by assembling a frame that consists of metal poles and plastic/metal fittings. Each pole should be labeled to indicate where it goes in the assembly, building a vertical, rectangular cube. The top side of the frame often includes at least one crossbar along the middle for hanging garments. The bottom of the frame may have multiple crossbars to help create a bottom shelf where drawers or shoes may lie.
If the closet comes with wheels, you will usually fit these into open ends on the bottom corners; you may also need to screw them in place. For the walls, the closet will have a large sleeve of canvas or plastic that slides or wraps onto the frame. Place the canvas/plastic cover on so the zipper part is in the front; this is the door for the closet, which usually works as a flap.
If the closet comes with drawers, nail or screw the pieces of the drawers together, making sure you securely attach the sides to the bottom. There are multiple ways of storing the drawers in the closet. Often, you will simply place them at the bottom of the closet and stack them one atop another. On some models, the cover will include inner sleeves that the drawers fit into.
Upkeep
The best way to keep a portable closet in good condition is to know exactly what you are storing and get the type of closet that will work. You should only get a closet with a plastic covering if you are storing soft objects like sheets and pillowcases; use a canvas closet for anything else.
If your closet's frame does not include crossbars on the floor, the load you put on the closet can take its toll. The closet will sag over time, which makes it more and more difficult to open the zipper. It can help to add support to the closet floor by placing boxes underneath it. Drawers can also work if there is enough clearance underneath the closet.