ŋA year? Thatīs nothing. I tried for two years!! It was a lot of suffering as you can imagine. So, I think you can imagine too that I wonīt share the secret so easily. But, I watched all You Tube videos about it many, many times. I can advise you to make first lots and lots of drawings from real life objects. The truth is that there are many ways of doing this kind of drawings but the basic idea is the basic drawing in the old way. Remember, renacentists created this efect when there were not digital cameras or computers. I wish you good luck. If you have succes, please show me your work, if you donīt, then, perhaps I can tell you something more about it.