I'm using Paint Shop Pro 7 (sometimes version 9) but everything can be done in any other program. (well, there might be one exception for one Effect, but it is not important, and I suggest some alternatives)
» Draco in Hell : (really easy)
1. Create a New Raster Layer and Fill it with the color F8BF24 then set it to Multiply 30%
2. Duplicate that colored Layer and set it to Saturation 30%
3. Duplicate it again and set it to Burn 15%
4. Duplicate it one more time and set it to Dodge 3%
5. Add this light texture made by neke for the effect of "Flames in Hell" set to Screen 100% then Merge/Flatten all Layers, and you are done.
» Weasley Twins in orange colors : (again, it's really easy)
1. Duplicate the image as a new Layer, click Effects > Enhance Photo > Fade Correction : set to 45. (but that's not and obligation if you don't have this option in your program. You can "Ajust Levels" instead or set it to Screen 50% then Duplicate that Layer and set it to Soft Light) The base should now look like this :
2. Add this Light Texture by uglybusiness and set it to Screen 100%
3. Add this Texture by wash_when_dirty and set it to Soft Light 100% (the Texture was more grainy, so I used the "Blur" Effect to make it look softer)
4. Duplicate that Texture and set it to Soft Light 40% then Merge/Flatten all Layers, and you are done.
Please do not copy/redistribute those 2 icons as your own, use those Tutorials with your own bases. Feel free to show me your results ! I hope it was useful to someone, have fun :)
If you want to use one of those icons Credit me alexia_drake Please. Feel free to Friend me :)