Know the difference between a primary and a secondary survey. A primary survey is carried out for life threatening issues. It requires that you check the ABC - airway, breathing and circulation - of the person. If they cannot get air into the lungs, if they are not breathing or have no pulse, you must administer CPR.
A secondary survey checks for other medical and injury related problems. It involves checking for vital signs, doing a quick head to toe check, asking the victim about the incident and applying any necessary first aid.
Practice universal precautions. This means treating blood as if it is infectious, even if you don't think it is. You should always wear gloves from the first aid kit, as well as a pair of safety glasses just in case any blood squirts into your eyes. If you don't have gloves, you can make use of a plastic bag.
Be sure to wash hands immediately after providing first aid.
Don't give fluids to an unconscious person. Don't move the victim unless necessary for their safety because you suspect back, neck, head injuries or broken bones. Don't wait to call 911 until you have applied emergency first aid - call first!