Actually, the FSDS help file shows you - step by step - how to do it.
Basically, create part texture templates (which are bitmaps) and in your paint
program crop them to the square size chosen (256x256 or 512x512) repaint and
then assign - all shown in the FSDS help tutorials.

You'll have to experiment, though, with which application is best for a
particular part right/left, top/bottom, or wrapped....

Felix/FFDS
Pegasus Aviation Design

I am new to designing and painting Flight Sim aircraft using FSDS. Has anyone
got any tips or links to web sites that show me the best way turn my FSDS model
into textures to paint. e.g best way to dice and slice a model into textures,
then import into PSP and begin painting. There are plenty of tutorials out
there on RE-painting, but can not find any on starting from scratch.