One of the most famous polymer clay techniques is probably the skinner blend.
However, that’s not always so simple to obtain a nice and smooth skinner blend with fimo clay.
First, choose the colours you want for your skinner blend. Most of the time we use 3 (or 4).
Using only two colours will require a bit longer to obtain a smooth shading (excepted if they are really close colours). Of course, the closer the colours, the more your skinner blend is likely to look natural and nice. Contrasting colours may be used for a more “psychedelic” or joyful aspect.
Once your colours are chosen, cut your different clays into equal triangular pieces - here I only chose 2 colors, if you use 3 or more, your pieces will be two equal triangles for the sides and one or two other triangle(s) for the middle colors):
(You can have a look at this website to see what your colours should look like at the beginning if you use 3 of them)
These shapes will help colours blend together (but not too much, we don’t want a big piece of ugly plain clay, do we?). Stick the different pieces together to obtain a rectangular thick clay sheet.
Than use your pasta machine (thickest setting) to flatten the sheet. Clay pieces have to be “perpendicular” to your pasta machine (or, if you use a rolling pin, you have to roll in that direction).
Bend the sheet and flatten it again (fold first in the pasta machine). And again, and again and again… until the colours have mixed.