Direction for a right AH

Hi fellows!
A basic question, but important:
What is the best point to start drawing an AH circle?
According to the drawing I enclose, my way of writing it is 3-1-2-4.
Is the right movement?
(Just in the case, you have to write for instance "I" alone.  In Spanish, it's very common, the vowel "A" means "to")
What abour if you have to write any dipthong?
Osvaldo Castro

Attachment: asound.jpg

(by valo1969 for everyone)