How do I determine optimal bake time for a polymer clay sculpture?
If you burn your clay your oven is too hot. So turn down the heat a bit.
You can also put your creation into a box made from aluminium foil pans. This will protect it from direct heat.

You can also bake the clay multiple times. So create the bigger pieces first, bake them, add the details and bake everything again.

Another option is to bake everything separately and put it together using glue or even the varnish for small details.