I absolutely agree that Ask and It Is Given is one of the absolute best books about the Law of Attraction (at least of the ones I've read - about a dozen). I may even like Hicks' Money and The Law of Attraction more. I have wrote notes and left flags on nearly every page of that book.
For me, I didn't find Law of Attraction activities to work for me well or consistently until I learned to clear my blocks.
I would send out that "rocket of desire" of positive expectation, which would be a clear request to the universal powers. Then I would, over time, negate the request with doubts or any sort of limiting thinking.
For me, EFT tapping (Emotional Freedom Techniques) has made all the difference. It has given me a simple tool I can use myself, in just a few short minutes, to clear away the limiting thoughts and emotions - and even their source. Which is usually some painful childhood event.
I'm now working on hunting down and changing any limiting beliefs that are holding me back. EFT is great at clearing them, they can just be a little challenging to identify.
Lynda Dahl, in Ten Thousand Whispers, another terrific LOA book, talks about how to find your limiting beliefs.