When I make textures, I ALWAYS work in a large format then scale it down. that does several things. One, it creates a finer panel line. for better definition. Two, it helps the colors blend in better. Three, details are defined better.
When I do my aviation profiles, I sometimes have well over 200 layers of detail, colors, panel lines, shading, highlighting etc. Each layer is adjusted for the correct opacity that I am looking for. When I am done, I create a png file from that large multi layered drawing that is reduced down to my target size. The textures for the GTF Ezechiel, the GVF Shu and others that I did have been done in this fashion.
Hope this helps!
All the best,
Jadehawk