Well, I've not read what is written in the hub How to Surmmon Your Guardian Angel, but I know by mine own personal experience a technique which i describe thus:
Get a fairly new Bible which has not been defaced. Place it on a table or flat surface. Visualize a holy man standing before you. This should be your kind of man you'll love to have as your mentor. Ask him what you want to know take him into some discussion fixing your gaze at him. Then proceed to open the Bible with your left hand and start reading from the first verse of the right side page of the opened Bible.
Before you read up to seven to eleven pages, the holy ghost before you should have ministered to you through the Bible. All you need to do is to interpret the content.