I think with any trick you learn in steps. For me I started just by getting the right throw. Once I had a throw that had a good axis of spin I worked on going around both fingers. I tried to keep the string all on one line as I felt more success if I landed on all the strings rather than not landing at all. With more practice things started to slow down and I could work on string placement on my fingers and bam it just happened. After a week around 15 mins a day it seems easy now.