I want as much of the body weight to be towards the rear, but don't want it to be overall too heavy, so a couple of weight-relieving chambers in the front horns will be helpful. I like any use of router to be fully captive, so use the same approach that I use for pickup chambers...
I start with a Forstner bit to hog out the bulk:
Then use chisels and carpenters mallet to accurately cut the outline to around 10 mm deep:
And then, and only then, use a top-bearing router bit to smooth the sides and cut to final depth:
And, as I have the router out, I cut the channel that will be between the two pickups and through to the controls chamber for the cable runs: