I've done this in the past, but not at the suggestion of a therapist. The way I think of law of attraction is more along the lines of this: focusing attention on specific things (people, places, ideas, values, etc) makes us look for more of those things in life. So we're not actually drawing them to us, but we're more drawn to them. For example, when I'm interested in buying a particular car, I see that car everywhere. If I wanted to generate a particular experience in my life, and I put it in front of me as a reminder (whether that's a vision board or something else), I would start to see opportunities to do that thing--so it's not like those opportunities heard about my intention, but more that I got focused on it and, by focusing, can see it around me. I've done that with my business (only, not with a vision board so much as surrounding myself with the type of work I wanted to do) and it's worked really well.