This  juniper was a large nursery tube stock 2 years ago . It was planted on a piece of volcanic rock , potted into a large pot to allow for root run , selectively pruned  and power feed for 2 seasons . The trunk was basically trained with a bit of movement then left to grow on .When left untrimmed , root pruned  they quickly double/triple in size from the small stock plant  , allowing for a nice specimen to work with . I find most people hack these back too hard then regret the butchering and loss of jin material . The foliage that is left will still pump the small trunks to a reasonable size ,  then they will be removed for the jins .I estimate another 2 seasons of power feeding then the branches will be stripped and the final style will take place I have wired the future jins and spiraled them like a cork screw , this will give them added depth when completed .I have slip potted it, rotating the tree about 45 degree’s to show off the rock and the movement of the trunk .  The  training pot is about 30 % larger than the previous for extra root run . When slip potting i never root prune as this would defeat the purpose of using a bigger pot , simple tease the roots out and repot as per normal potted plant adding plenty of slow release fertilizer above the root-mass . I  hope to have a tree resembling this sketch in a year or two . Cheers Alpineart