It's a good start for sure.
The wiring looks neat and the pads are well defined.
Just one thing I want to point out is that the lower left branch is as thick as the apex of the left trunk. The left branch also has more foliage than its apex. Meaning that over time, the branch will likely outgrow the apex. If you envision this plant without the wire, yes, it's logical that the lower branch is older and should be larger.. But combine the foliage excess and relative size, and it will also end up being the fastest growing part and thus elongate further than would fit the image in the near future.
That's why I prefer working/clipping junipers outside -> inwards. Keeping the smaller branches close to the trunk and growing those out to fit the design. In this case, I would have worked that branch back instead of keeping the outer foliar mass.
That's literally all I have to add. All things considered, this is good work. Nana buds back easily, so no need to do anything else for now, but any other type of juniper will be less forgiving in that sense. If you keep that in mind for the future, I bet you're going to make a bunch of awesome trees.