It can be hard to create a system or structure with regard to the imagination because by its very nature it does not conform to structures or anything approaching rational principles. The best thing that you can do is to really commit yourself to a creative process and watch the magic unfold.
One of the best strategies is to:
(a) Create 100 paintings in a month.
(b) Write 1000 creative words each day for a month.
(c) Try to visualize yourself in a desired setting at intensity
for 10 minutes each day.
However, it is almost amazingly difficult to get people to do these simple tasks. This is because people always want to know “why” and reach a rational goal. But these processes will shake up your mind and open up your creative consciousness. You will gain insights from your paintings or writings along the way. In fact, you will get better results if you do not have a goal in mind with these writings/paintings/visualizations, such as a monetary reward. If you can do something like this the benefits will be huge. As an additional piece of advice, you don’t have to learn how to paint in any way or even how to write or visualize the ‘correct’ way. These are your creative works. Just do them and reap the benefits of your own imagination.