There are Angels all around us. Some of us are aware of them, some of us are not. I work with an Angel who gives me the information for all Angel readings I perform.
There are all sorts of Angels for all sorts of things. If you are not sure on how to invoke one that is OK, there is no special way of doing it. If you ask, you shall receive. No Angels will intervene in your life unless you ask for help. We all have our own unique journey and it is up to us how we want to take that journey. My Angel is with me a lot of the time, but if I need guidance or assistance as to which direction I should take, I will ask.
My way of asking is: "Angel of Mine, I need to seek assistance if I may, I am feeling stuck so please help me with this situation." I will then talk to her about my situation. "Thank you my Angel." Then the key to is to let it go... Don't try looking for the answer when you have spoken to your Angels, don't ask them how you want that situation to come about, just know it will be in their way. They will show you certain things that you should be doing, again it is up to you, you are the one that has" FREE WILL".
You can ask anything of the Angels, as long as you always ask with the right intentions. I have many products for sale in my shop regarding Angels. Doreen Virtue is fantastic at teaching you about the Angels. I have her books CD's and cards which are worth a look if you are interested in learning more about yourself and the lovely Angels up above.