Here is an exercise: tell yourself something like "I am instant manifestor -I instantly manifest my reality. I am expression of All That Is which instantly manifests all now, therefore I instantly manifest too"
Ok you might do it for few minutes, enjoy the feeling of it, then look around with nothing much changed and think like 'this is a lot of bull' :-) To avoid the conflict with what is already manifested, though, you need to remember that You, a greater you whith which you are not currently all identifying with indeed does manifest instantly. In other words - part of what is currently being instatnly manifested for you is your believe that you are not an instant manifestor.
You can tell that mantra (repetitive phrase) to yourself before going to sleep too, that way you will set into motion powerful dream events helping you into being conscious instant manifestor faster.
Also you can tell yourself statements of fact like this: 'I am manifesting now this beautiful universe, I am manifesting now this lovely planetary body, I am manifesting now this delicious atmosphere I am breathing in, I am manifesting now this constatnly self regenerating body I am living through, I am manifesting now my delightful unlimited thinking' etc.
So if you want to be a deliberate instant manifestor just do it, keep doing it in your mind with feeling and then expect it to be - look for evidence of it happening in your physical environment - because you will notice it and ever more so as you allow more of your energy into it. And most of all - have fun with it! :-)
