Wait until the trees have all gone to color in your area when the tree is drier for and ready for winter. Juniper get less damage from the twisting and wiring in the off season. New foliage always points up at the sun, that's why we can wire the pads flat, sideways from the branch and the clouds then grow up from there and we tip prune everything to encourage back-budding. You tip prune all the ends of the stems you flatten that you want to maintain length/shape. Anything that is not long enough is left with the tip un-pruned. Adult foliage comes with time. When the tree has as much foliage as it needs to produce seed and mature it, it will begin to grow only mature foliage. Ignore the way it grows and just keep pinching for shape. Eventually, it will have enough foliage to evolve to mature. The volume of foliage you subtract will also contribute to immature foliage, so over time as you take off less and less, it will be necessary to replace less and less and one day you'll see only mature foliage emerging. Picking tips to maintain finished clouds is the preferred method, but you can also use a scissors to shape it like people shape topiaries. I use a 12" scissors that makes people gasp.