here a tutorial of the way I try to make N as well as HO and O trees...
I made an instant "how to make" from birch trees so I do not have to write so much in your language
Actualy you can use this for any trees you want to make...
The first birch( on the left!)shows a "frame"of a birch that is not benched in shape and is already been sprayed with primer.
The second one : I added the sieved coarse sawdust on the lower part of the trunk, and fine at the top. I did this with a mix off white glue,a very litlle bit of water,few drops of the stuff you(or your wife
) uses to do the dishes
and little bit acrylpaint. So you can see wich part of the trunk you have glued and wich not.
The third one:After drying I painted the whole trunk in a sort of white color(acrylpaint: mostly white with a very little bit of oker. Just a spot! After drying I "painted" the tree with black aerosolpaint. ONLY the outside twigs/branches. NOT the trunk: its a birch!
After drying I bend the branches/twigs in the right shape(Look at pictures of real birches from outside.)
Next one: Here I added the fibres on the twigs: The fibres were cut in very small parts/pieces(1/4 inc=<1cm!) and during the cutting with a sharpe scissor,I collected the cutting fibres in an old shoebox(Without shoes
DO NOT PRESS the fibres!
Than I took the frame and sprayed with aerosolglue over the outside
of the twigs(Do not spray near
the box with cutted fibres!) Back to the box I took carefuly some fibres and let it fall, from the top, down into the box. Repeat this one more time.
Now you have to remove the fibres wich are not glued, and that is, I think a little bit sticky! Because now the tree will have it's final shape before adding the "leaves".
At he last one you can see the tree with its "leaves"
I glued the leaves by first again spray the tree(outside parts of it!) with the aerosolglue and directly "throw"the leaves( coarse turf from WOOdland or flocken from Busch, Noch or Faller etc.) with a theasieve on the fibres. It does not matter from whom, but it has to "fit"with your own vegetation on your layout AND
it is a matter of taste!
At the end I always spray the tree twice with matt varnish(aerosolcan) to make it less vulnerable