In Feng Shui terms where is the best place for me to put my bed?

Im trying to feng shui my bedroom but its really difficult because its such an awkward room! To start with i have a sloping ceiling and a beam across the middle of the room, but my biggest confusion is where to place the bed. its not possible to put the bed in the far right corner - my only options are having the head of the bed on the same wall as the door (which is how i have it now) or having the head of the bed on the wall so that the door opens directly onto the bed. Which would be the lesser of 2 evils?! Can anyone help?