For the best views of Railfanning sit on the left(Platform) Side of the train and facing opposite to the Loco when it departs Marwar. Since the Train has a Loco reversal from Phulad onwards and the ghat looks spectacular from the right side, you'll surely enjoy the view. Also, try looking for an emergency exit to get best shots and if possible carry food as you wouldn't find much and a cardboard as the seat benches are hard and eventually your bum will start aching :D