A bad omen is something that you take as an indication of something that will happen. For example, you might believe that crossing paths with a black cat is a bad omen because it can bring you bad luck. Or, you might think that raining on your wedding day is a bad omen because it is believed that it will bring you bad luck.
Good omens are things that you take as an indication of something that is going to be good for you. For example, you might take it as an indication that you are going to get married in the next few months. Or you might take it as an indication that you will get some good news from some important people.
You might also take it as an indication that someone you know is going to visit you in the next few months. For example, you might take it as a sign that someone is going to come visit you who is related to your job or your love life.
The fluttering of a butterfly is also considered to be a good omen. It is believed that the appearance of a fluttering butterfly is an indication that you will receive some good news from some important guests in the near future.
Having a tingling sensation in your hands is also believed to be an indication of something good coming your way in the future. This is because astrology believes that the tingling feeling means that you are going to be wealthy in the near future.