First of all, it is very important to avoid sleeping with the head towards the door. According to feng shui, the proper position in which to have the bed and to sleep is in such a place that allows us to see the door but without being right across from it. This way, you should always avoid sleeping with your feet right in front of the entrance.
It is also highly recommendable to avoid sleeping under a window.
Sleeping right under a window would have a bad impact on your chi as well as it might cause you to lose some of your positive energy by dispersing it. Also, if your bed is right under the window, any bad chi which could enter into the room through it would go directly to you and therefore affect you. If you can't avoid sleeping under a window, then you should hang a curtain that doesn't allow bad chi to enter.
According to feng shui guidelines, it is also recommendable to avoid having pictures of water in the bedroom. Keeping pictures of water in the bedroom can cause insomnia as well as attract bad luck to those who sleep in the room. Therefore, if you do have a picture of water in your bedroom you should remove it or at least make sure it is as far from the bed as possible.
It is very important to make sure that there isn't any poisoning arrow pointing towards the bed. In order to find out if there are poisoning arrows, you should check for any edgy element or corner which might point towards the place where you sleep. If you find any and you can't get rid of it, you can neutralize its bad effect by covering it or by placing a plant in front of it.
