Buy all three books by Eric Broug:
Islamic Geometric Patterns (2019 edition).
Islamic Geometric Design (2013).
Islamic Design Workbook (2016).
With this collection of books, you will have all the knowledge you will need to learn how to understand and draw these patterns.
Eric will sign the books for you. You can also buy these books for friends or relatives, and Eric will sign and dedicate the books to whichever name you supply.