In this video, I show a technique for making cheap and fast silicone mold using silicone caulk and corn flour.
For the original recipe, google Oogoo
The materials cost about Rp.30.000 (about US$3) so it's very economical. Be wary though, the acetic acid used in the caulk can be too strong for some, so doing this in a good ventilated room is recommended. Use a respirator too.
The key here is the layering. Do a thin layer to get all the surface detail covered. Then add more silicone to make it stronger. You can play with the ratio of the mix. By mixing more flour, the mix will be more pliable, less sticky and cures faster. So this is good for reinforcing the detail layer.
You can also thin the dish washer liquid slightly and put it in a spray bottle for easy access and clean up. The soap will act as a barrier and will keep the silicone from sticking from your hands and tools. But it can also keep the silicone from sticking to each other. I didn't show it in the video, but you might need to wipe out the soap residue before layering more silicone on top.
This technique can also be used to make texture stamps.
Give it a try and happy sculpting!