Response to the challenge of the box: On cloudy days, just leave. On sunny days, go to a patio or use a thin white sheet over a large window. Alternatively, you can build a scrim using PVC pipes and anything that diffuses the light (the sheets work well, I also built one with a more industrial version of parchment / waxed paper).
How to properly use 2 domestic torches to take Photo indoor ?: Use the same principles as the previous ones: put something thin in front of the torch to diffuse the light. However, two torches will be so dim that you will need to use a tripod and a very long exposure to avoid having to manipulate the ISO. Alternatively, experiment with light painting (however, this probably will not work well since you will end up having a "scratched" image.) This technique is not normally used to illuminate illustrations, but is used to create interesting images).
Do not be a cheap answer: Yongnuo manufactures some cheap speed lights that could be used, or you can try to find a used speed light in good condition. The rebound of these on the ceiling / wall will work well to diffuse the light. Studio Strobes can also be used often, or an entry level or similar AlienBee400 can also be purchased at a very low cost (in the grand scheme of things).