Hi Laura! Thank you for this class and was a lovely quick exercise :)
Here is my final sketch:

I could't resist on adding a bit of color! 

About the process:
Here is the reference photo:

link

First I made a quick pencil sketch

Then the first marker lines:

Then I erased the pencil lines but it look too simple and thin

So I used a thicker marker and changed some of the lines

Last but not least I added the dots!