Styling/pruning for structure

Hello everyone,

right from the start - I am completely new in bonsai hobby. So I started to read articles and ebooks for like 14 days and have some questions about structuring trees.

For example i want to make some area of a tree more dense or i want to spread branches to some direction. So i want to "divide" one branch to two...
I found some picture how to do it:
https://imgur.com/VgVah7b
And my questions is:  Is it realy work this way? (like on a picture above ), Is it possible to divide any branch this way or it must be "younger" branch ?
Is it possible to do this with juniper trees?
Do I have to treat branch somehow before/after the cut to make this happen?
And finally i expect that the best time to do this is in the growth season?

I very appreciate every feedback from you guys.
Thank you and have a great day.

What you have shown is simply pruning the branch back to a pair of buds and letting them develop into branches. This is a very common technique to develop more ramification (more smaller branches). It can be applied to any tree that has buds that can develop behind the cut. However, some species like pine have few buds or they are difficult to get started. On the other hand, trees that are naturally bushy or have definitive growth nodes will often bud back.

For junipers it is more common to allow the shoot to grow and produce side branches. Those on alternate sides of the branch are selected (others are pruned back) and perhaps part of the central leader is cut back. This will start to develop the ramification. Cutting back evergreens like junipers and not leaving any foliage often results in branch dieback.