For instance:

• Folder templates require several layers of transparent PNG files, plus some vector parameters to properly resize and warp images to fit in all modes.
  
• Color packages require understanding how ImageMagic works internally to properly apply RGB and hue values.
  
• Textures may be easier to build, but some params are set in XML files. This made some coding knowledge required.
  
• Add-on icons must be made in high and low resolution sizes.

Sadly, I can't dedicate time to make the modules for self-made elements at the moment. But if you have some ideas (like add-on icons, color or texture packs), you can provide source files and samples to me and I'll gladly make the rest and release them.

Ok, I'll give myself some time and make some extra packages. Though folder templates and textures are more difficult to build, textures are less problematic and colors even less, so I'll start with the easiest ones and scale up.

Gladly, I recently discovered a very good source of royalty free icons: http://downloadicons.net/ ...I'll build a few add-on icon packages from those.

I hope to be publishing at least a couple of packages before the end of this month, then make everything possible to publish at least a package per week for a couple of months.

example

To be able to import other folders to use in program for crafting

Import other folders? Do you mean... When you're crafting an icon, set it to multiple folders instead of just one when saving?