A given flourish can take days, weeks or months to master - entirely depending on its complexity and required dexterity. As you become more experienced, new flourishes can be mastered much faster. The basic formula is below:
1. When learning the flourish for the first time, follow along with the instructions very slowly, "cheating" if you have to by helping yourself execute the flourish in a way that is not intended, just so you can understand the basic movements.
2. In doing this, memorize the basic movements of the flourish - but with no intention of doing them quickly yet.
3. Continue to practice the movements. As you find yourself able to do it well, try doing it a tiny bit faster.
4. Slowly work it up to being quicker and, more importantly, smoother.
Your ultimate goal is smoothness, not speed. Once you're able to execute the move easily speed will also come naturally, but your goal is to be smooth and fluid.
Also, a very important tip - take breaks. If you're having a bit of trouble with a move, stop practicing it and come back to it in a few days while you work on something else. If you do this, you will find that you learn the moves much more easily and don't have as many "road blocks" to mastering them.
Let me know if you have any questions.
All the best,
Vinnie C.