Charles Haanel says so succinctly that "the image is the mould or model which will serve as a pattern from which your future will emerge." It's exactly like this. First the spiritual, then the material, never the other way round.
First you create the image of your Ideal in your mind. The nice thing is that once you've created it, it already exists, and once it exists the very thing that can go straight out of the window is ... doubt! Why doubt if you know it's already there?! All you have to do is "densify" it, read: lower the frequency by adding more energy and attention to it, thus allowing the electrons to arrange and align themselves to form atoms, then molecules, then crystals, then real matter.
Later on you will learn how to concentrate yourself, because when you do this in the stillness of whatever place you've chosen, you will get inspired in the truest sense of the word. Under meditation and concentration you will get informed about how to go about reaching your goal, but in order to reach it you first need a very clear picture, and that's what your visualisation skills are there for. The clearer the picture, the easier it is to manifest it.