You may have a lot of affection for your golf clubs, but the reality is that every club can be a weapon, too. Yes, practice swings are good for your game and help you loosen up, but it's a good idea to look both ways before taking that swing.
If you swing nonchalantly and hit some stones, pebbles, or twigs that suddenly fly off into the air, if someone else is in the vicinity they could get hit and get hurt. When in play, whenever you strike at your ball make sure the other players nearby or ahead of you are out of your range. If they're way in the distance but in line with your ball's trajectory and the ball will be landing close to them, always shout the warning “Fore!” Better safe than sorry, anywhere, especially out on the course.