Once you are hurt, get into a comfortable position and when you can handle it, put some pressure on the bruise with your hand. A bruise can hurt a lot and can make breathing difficult. Do not put too much pressure as it can create more trouble.
In order to soothe the bruise, use an ice pack on it. You can get one that is available in stores for this purpose. If that is not available, you can also opt for some ice and pack it inside a plastic bag. Wrap the bag in a towel and pace it on the bruising for around twenty minutes.
Take a pain killer every 6 hours or so to relieve the pain. You can get any of the over the counter pain killers and ideally take it after you have consumed some food. If not, drink some milk with the pain reliever since they can hurt your stomach if you have any kind off gastric trouble.
Do Light Exercises
As the pain reduces, do some simple exercises by lifting your arm and slightly rotate it. Do not do them in a hurry or too intensely and make sure that you do them in a careful manner. You should be able to improve the motion as the time passes and the effects of the bruising reduces.
Rest well and do not perform any tasks that need physical indulgence. The more you let your shoulder to rest, the quicker it will heal. Keep it warm as bruises can hurt more if they are exposed to colder weather.