A question that comes up frequently in regards to manifesting using the Law of Attraction is, "How do I make the process work CONSISTENTLY?"
In one word, the answer is 'Practice'.
The more you work with the system, the more consistent your results will become.
The more you work with your beliefs to expect positive results on a consistent basis, and the more you develop your willpower to hold your focus on what you want long enough for it to manifest, the more consistent your results.
And the more 'real' you can make your "mental template" within your imagination, the better the process works.
Consider what it takes to get consistent results when playing a musical instrument, or in photography.
It comes down to knowing your tools, knowing how to use them, and being so familiar with them that you do the right things at the right time without thinking about it much.
The same is true in manifesting your desires.
The more you know your tools (belief, willpower, imagination), and the more familiar you are with working with them, the more you will do the right things at the right time without a lot of thinking.
To put this another way, recall your experience when learning how to drive a car.
At first, there were so many details to keep track of. You may have even lost track of one or more, possibly coming close to having an accident.
Yet, over time, and with practice, you learned to manage all those details, and eventually reached a point where you can manage all of them without a lot of conscious thought.
The answer to getting consistent results in anything is simple -- practice, practice, practice.