I never used a program like photoshop or gimp before I tried to design for Achat. It took me at first much time only to adapt to it and understand the possibilities. And I still learn a bit each day.
The first hardest thing is to get used to the functions of the programs. To know what they do and how to use them.
The second one is to understand how the cloth map applies on the character to be able to cut a model out of the basic diffuse provided by Achat.
Sometimes a straight line on photoshop gets curvy on the final result because of the relief effects.
For the first one, each program has youtube videos or sites that explain each function thoroughly. Just type your question in google, and you'll come on one of these.
Like: photoshop+how to resize layers? gimp+how to move a selection? How to create a light effect? How to use patterns? how to create fading effects? ...
Watch a lot of vids and read the program tutorials.
Tutorials for photoshop:
http://www.tutorvid.com/category/photoshop-tutorial/Tutorials for gimp:
http://www.gimp.org/tutorials/For the second one, any tutorial vid, is it for 2nd life, i.m.v.u... is good enough to get the basics to create clothes. Then adapt it to Achat ones. Only the shape of the basic diffuse is different.
After that, it is just a question of trying, trying, and trying again.
Basic "rules" and ways to work:
- open your chosen diffuse : go in files-open-<cloth diffuse>
- rescale your image in: image-rescale. Options: size 300%, 300dpi (will add much more detail)
- duplicate this layer : right-click on layer, duplicate this layer. So you always keep the basic one untouched to be able to see how and where to cut it right. Make it "visible" to correct, then "invisible" again when needed.
- cut your diffuse in the wanted shape: Use selection tools to delete the unwanted parts of the diffuse. Any transparent part just won't appear on the final result.
- adding colors and patterns: use selection tools to add the colors where you want them on the diffuse.
- adding images or patterns: open your saved image (like the flag symbols, the jewels I used...) as "new layer" in "open file". Delete the unwanted parts of it using "color selection" or other selection tools. Then place it at the right place with "moving layers" option.
- once all layers as you want them, save your image as "PNG" file. The layers you worked on but you don't need for the final result have to be invisible. Only visible layers will stack and appear on the character.
- keep loading your diffuse on Achat at each step to see if your cuts and colors are right. To see where to cut, just save all layers and the basic diffuse as "visible" on the character, and you'll be able to see how they appear and adapt on it. Keep comparing and adjusting.
- the height map : is almost only your finished work reworked in black and white (grey too) colors. Save it separately from the colored cloth and load it additionnaly as height map on Achat. (white is height, black is depth)
I know this is quite a very basic tutorial and doesn't explain much. But I hope it helps a bit. For the rest...keep on watching tutorials on the web and trying.
It just takes time indeed. Be patient with yourself and you'll come to some results for sure.