If it's serious, call 999.
Look for danger - you don't want to cut yourself.
Never remove glass from the wound.
If there is no glass in the wound, then put pressure onto it with a tissue.
If there is a lot of bleeding get them to sit down.
Apply direct pressure using a pad using fingers.
If there is something in the wound, apply pressure either side of the wound, NOT directly on it.
If you can, raise the injured part.
If they start going into shock, raise their legs.