I made this forest with some dwarf pine trees or Picea Glauca ‘Conica’ in Latin. This was my first attempt of a bonsai forest and I am quite happy with the result. This makes me think of the Belgian Ardennes where there are many pine forests. 

Of course the wired branches still need to set and the trunks and trees have to grow. In about a year the roots should have clumped together which makes it a lot easier to repot the whole lot in one piece.

With a forest it is always important to make it look like the real thing. That's why almost always the smallest trees are positioned in the front and on the sides of the pot, to give it the right proportion. Normally flat oval pots or flat natural stones are being used as a base for forests. Some forest are even built up as if the trees are growing on the side of a mountain. You should find some magnificent examples on my Pinterest account.