i would say, choose a theme just for that space and work around it! for example: maybe "asian" theme! paint the back wall RED or ORANGE, have a piece of buddha statue on the top most rack, you can use one shelve to just hold books with some decorative book ends, and instead of the chair, you can use the asian trunck boxes (if you google for asian trunks, you can see what i am talking about! - look for square boxes), this way, you can also tuck those boxes under the desk/shelf when not in use and the trunk could also be a storage for your files - you can also place a floor vase with some bamboo sticks - the asian theme would really work here as your wood is black/brown this would also turn out to be a peaceful writing space - enjoy!

Pankaj, I just realized that initially you told us that the bathroom area was 12'-0" x 9'-0" and later you mentioned that it was 11'-8" x 8'-0". In the last floor plan, I forgot to change the bathroom with the new dimensions. Below is the floor plan with the correct dimensions for the bathroom. The bedroom is ok, I drew it 19'-2" x 12'-6". The new layout does not change the way things are placed. Everything still fit. The only difference is that the vanity is now 4'-4" long instead of 4'-8". and the toilet is closer to the shower by 1'-0". Can you give me the lengths of the walls K and L. They are the walls between the vanity and the shower area. I will send you the new layout once you give me the length of these 2 walls.

In the above images, the first and the last are part of the same door. I used silver pendants from an antique store to embellish the doors

I suggest you follow the step-by-step guide for creating storage cabinets under the bathroom sink. Take proper measurements - Measure the available available space in height, width and height. Cut Plywood to size - With a circular saw and framing square, cut all the required pieces out. You can use a sliding compound saw as an alternative. Attach the base and sides - Start assembling the sink cabinets by placing the bottom piece of plywood sheet on a flat surface. Attach the back and top boards - Place the plywood sheet for the top part of the cabinet and attach wood screws to connect it to both the sides. Turn the back faces of the cabinet upwards. Keep the back piece over the structure and fix it into place with wood screws. Attach shelves - Place the cabinet in an upright position to install the shelves. Slide a shelf into the structure so it is flush against the back. Attach door - Keep both hinges of the door on the same side of the plywood sheet. Drill them using wood screws into place. Now keep the door over the cabinet structure, extend the hinges to one of the side panels and fix them to make them secure. Fix a hasp closure on the other side of the door, placing it in the center of the hinges.