Study your room for an area with an alcove, recessed area, or even a small hallway or side-room.
Measure the width of the recess or doorway. Purchase an adjustable tension rod or curtain cable for that area.
Purchase or make curtains to fit the dimensions of your alcove. Attach the panel to the curtain rod.
Mount the rod or cable per package instructions.
Bring in portable storage if space permits in your alcove. If you're using it for purposes other than storing clothes, furnish accordingly.
Remove the door, or doors, and hardware from your closet. Leave the space open or plan to install a curtain based on whether you want the nook to be visible and how much room you have.
Remove any unwanted shelves or clothing racks. You may be able to use one to hang and store certain supplies if you're creating a sewing or craft nook, however, or an office.
Install a desk shelf for an office nook, or use a current shelf if its size and height work well. Choose a small chair or stool that will slide under the desk and save space.
Paint the nook a desired color or cover it with wallpaper.
Install any desired cubbies, shelves and portable storage.
Place a small bookcase in the space for a reading nook or store books on existing shelves.
Furnish a reading nook with a comfortable chair and a side table, or use an existing shelf as one.