Hi Tuomas

I use Holdfast's method: panel line wash or this method: panel lines with pencil lead
If you click the links the thumbnail pics don't show but click them and the full size pics do appear.

I am by no means an expert on this subject.
I use enamels for my wash. I use the same technique as Holdfast with the exception of using the enamel paint instead of oils. I think the important thing is the "Future" coat application, this will protect the underlying paint from your wash. Make sure this coat is fully dry before applying the wash.
I hope you luck.

Ted

Ive tried the oil/turpentine technique a few times and couldnt get it to work for me very well. Im still experimenting and trying to find which technique suits me best but for the last couple of builds Ive been using heavily thinned acrylics and Ive started to have some success.
From personal experience its a question of reading the excellent articles that people have referred you to and trying different techniques until you find the one that suits you best.
One things for sure,,make sure you have plenty of Future to protect the paint underneath and help the wash flow.
Hope this helps
Nige