When redoing a painting to 'match your inner vision' all decisions must be based on the original idea. You can review the earlier videos in this series that show how to find a spark of an idea, what mark-making means to you, and how media might influence your painting. Understand that your personal urge will be different from mine or another student's. This video shows how oil (or watercolor) painters can modify and adjust a painting and go beyond photo reference.
Watercolor painters can use the ideas presented here to make use of glazes and washes to modify shape, color and tone, or use gouache over an existing painting.
Although some students might think this is an advanced lesson, really the project is very simple. The only difficulty lies in how to maintain focus and not to grab the photo for answers. What to leave out to simplify the visual message is essential. Make it personal, this is your choice as to all decisions. The 'copy' mindset must be fully left behind, instead think of distilling the focus and choosing what to put in. Simple is best. Detail is not the answer.