phone <> ESP8266 spaceship

I've got an annoying problem.

The ESP8266 resets itself intermittently- my guess is that it's power fluctuations since I've got 2 DC motors riding on it. The forums are full of people with similar issues, but the solutions aren't the same per problem. I'm using the Adafruit Huzzah Feather, which probably has a bunch of stability rolled into it.

Step one: separate the Huzzah board from the motors and see if that fixes the problem.

Step two: add a bigger capacitor to the motor power rails (I have a 2.2uF there currently). The motor is powered from 6 AA batteries.

Step three: do some of the stuff that people suggest works in the forums, like downgrading to Arduino 1.6, flashing with Generic ESP8266 and pulling GPIO up or down via hardwiring. This all seems flaky to me though.