Most Junipers thicken very slowly. Allowing some sacrifice branches to grow real long definitely speeds up the thickening but I still find it's a 6-10 year process.
When looking for the tree hidden within don't be distracted by everything that's currently there. Much of the current tree will disappear to reveal the bonsai.
I usually break the design into chunks to make it easier.
First check roots for best view of nebari.
2nd check just the trunk for best bends and trunk movement. Concentrate most on the lower parts which are thicker and harder to change. Upper trunk can be bent or regrown a a better shape. Remember to try other planting angles (wedges are helpful to prop the pot to one side or another or front to back. Keep turning the whole tree to look for better and worse trunk shapes.
3rd look at branches. Which are well placed on the trunk bends. Do some look better from one 'front' or from another viewing angle.
4th look for any features that you'd like to show people.
5th look for any faults you'd like to hide.
I find that most younger and nursery stock plants will not have much in the way of features and faults.
Finally, try to match the best views of all the above factors to find the best viewing angle. We rarely get everything aligning perfectly but a compromise between 2 or 3 best views might be the best option. Maybe removing one branch will give a much better view of the trunk? Try different combinations of roots/trunk/branches to find the best potential.
In most cases you'll find more than one good option and then decision paralysis sets in. What if I choose the wrong one? Even though there may be a few great options you can only make one of them. If all look equally good it doesn't matter which you choose. If necessary toss a coin to decide but make a decision and get on with developing that tree. Once you make a decision it automatically becomes the 'correct' option.
It is always hard to be sure of styling a tree from 2D photos but The first pic you posted above seems to have most potential.
There's lots I can't see in the photo like where each branch starts and which direction they grow in so always check the plant to see if any online proposal will actually work with the trunk and branches you really have.
View attachment 542922
Blue should show a nicely shaped trunk line.
Brown indicates proposed changed upper trunk line - either wired into position or grown from smaller side shoots.
Green indicates probable branches and upper crown. Need to check the tree to find where there are possible starters for the branches to be. You might like to have a couple more branches if there's space and they are available but generally less is more in bonsai. Just include sides and back down low and more all round near the top.
I'd also love to see a view of the trunk with this tree turned about 90deg anti clockwise from this current view though that could put the best branch toward the back so may not be a better option.