Hi! Stumbled upon a relatively easy way of making bug eyes for my kamen riders, and I'm fairly new at it though I thought this might be of interest to I took time to document the process.
Okay first you have this head sculpt, with the eye sockets drilled in, this is mainly to center the eyes for setting later.
Next you put some epoxy putty in the sockets, just enough to fill it and to jut out slightly from the hole. Make sure you make the shapes the same.
Then, using a dental tool or a hobby knife, make a criss-cross pattern on the eyes, this serves to give the compound eye look to the final product.
When the putty sets hard, paint the eyes silver, this is so they reflect any light that hits them, and makes the finished eyes stand out more.
You'll need some fast setting clear epoxy for the next step, mix a tiny batch up and wait for around a minute or so before using it on the eyes so it won't run.
With the dental tool or a toothpick, gently dab a drop, roughly the size of the eye socket on the criss-cross pattern use the tool/toothpick to position the drop into the right shape while it's still fairly fluid.
once you get it the way you want, simply paint it up with the clear acrylic colors of your choosing and you're done! this method also works for henshin belt orbs or monster type eyes as well, as always, practice makes perfect!