1. Method 1: a tutorial produced by Dragoart, real easy one, 10-15 minutes of work.
2. Method 2: a beautiful tutorial by TLC. I can't help it, I love their tuts!
4. Method 4: a video tutorial by OverNight artist.
I hope you find them useful.
It was interesting to draw an Iris. The fact that I have them grow in my town every spring and drawing these from photos is obviously, absurd. But for some reason it is always easier to draw from a photo than from a live object.
I hope I will be able to change it soon enough.
Have a great day,