In the next few days, I will be totally busy with testing the standard tools and finding out how to work with them correctly. It is already obvious to me that there is not "one single solution" to achieve something. In this case, Illustrator and Photoshop do not differ at all. But of course I try to use the most efficient way from the beginning, so I don't have to deal with questions like these in the long term. It is easier to adjust contours and repair mistakes than in Photoshop. - Even if you don't back up layers after some editing, which seems to make Illustrator much more suitable for projects where regular and numerous concept changes are normal.
Compared to Day 1, it was a little more tricky to create abstract and geometric shapes like rectangles with rounded corners, linked circles or spirals. Nevertheless I was already able to find out much more efficient and accurate ways to work with shapes like these compared to Photoshop.