Angels are high energy spiritual beings. And because of their high vibration level they exist just out of our range of sight.
You can compare this to, for example, the dog whistle.
Although WE can not hear the sound that the whistle makes, dogs can. So even though we can not hear certain sound waves doesn’t mean that they do not exist.
Some people’s hearing range is bigger than that of others; they are capable of hearing more higher and/or low sound waves than the average person.
It is the same with Angels. Even though we do not always see them that doesn’t mean that they are not there.
But we can train ourselves to raise our vibration level and by doing so,
we are more likely to pick up the vibrations of the Angels who are around us always at any given time and place.

Although Angels don’t experience emotions like anger, rage, fear and so on they do understand those emotions
Some people believe that there are a lot of rules to be taken into consideration when you work with Angels,
I personally do not agree. The Angels assure me that it doesn’t really matter how you call upon them, they are not bound to any religion but respect every religion.
You don’t need  prayers per se, but you do need to invite them into your life.
They can not help us without being invited that would interfere with our free will. If we choose to make life a struggle and don’t ask them for their help,
they are banned to the sideline, where they eagerly await our request for their help.
The only time they can interfere without being asked, is if our life is in danger and we run the risk of being taken away before our time.
This is because it would jeopardise the greater plan we agreed upon before we were born into this life.
But I do believe (and this is my personal opinion) that we have to follow certain rules of engagement.
Be polite and friendly; always thank the Angels for their help and/or actions.
Treat them like they are your best friends, and to be honest, that is what they are … our best friends, and would you treat your best friend by being rude and impolite? I don’t think so, I know I wouldn’t.
Sometimes people say ‘I have asked so many times to win the lottery, but it doesn’t work’.
Again the Angels know the total picture and just to give you an example, would you give your child loads of money if you would know that it would only spoil him or corrupt him and withhold him from the opportunity to learn the things we agreed upon according to the blue print of our life …?
Think about this!

Another thing is that Angels will never help you to hurt another person.
They always consider the greater good for all involved and to put this in perspective the Angels have given me another example.
- you really would like to have the job your manager or supervisor is having, but if that person is in that position for a reason and that has nothing to do whether you think he or she is doing a good job or not, you will not get that job, but there will be another opportunity for you, maybe another position within the same company, maybe the same position with another company –
Always trust the Angels to come up with the best solution for all involved, So keep your requests for help as open as possible, don’t give your Angels a script to work with, they will do what they can within the boundaries you have set for them, but they can only perform miracles if you let them have the free hand.

The Angel will do what they can to smooth your life as long as it is within the Guidelines of Spiritual Law or Free Will.

I can only advise you to make the Angels part of your daily life. Ask for help as much as possible and don’t feel worried or guilty about asking for their help. You are not taking them away from anything or anybody, you are as important to them as the next one. Angels don’t pull rank. Things like being a Queen, President, Boss or just being rich doesn’t mean anything, we are all equal to them and are equally loved by them.

In one of the many books there are about Angels, I read about the topic of asking for help and whether or not it is appropriate to ask for small things. I just loved the answer the Angels gave on this subject. It was so clear and understandable:
“Would you only call the fire department when your house is already engulfed in flames?”
The wise thing to do is work with them and make sure that the chance of a fire is as small as possible.  
I love this answer, they really want to be a part of our lives and help us in any way they can to make life as smooth as they possibly can, but they can only do that when we invite them to become part of our lives