In previous ESP8266 projects, I have used the NodeMCU Vers. 0.9 as a target board.

Figure 1: The NodeMCU 0.9 board with the ESP-12 removed

The NodeMCU board is super convenient, you only need to press on the download button in the Arduino IDE. (no holding of buttons on power up) But, the LED lighting controller needed to be as small as possible. So, to handle the downloading of new software, a NodeMCU board had the ESP-12 removed and the 6 control/power wires attached at the correct places on the lighting controller board.

Figure 2: The external programmer for the ESP8266 on the lighting controller (the NodeMCU board removed)

I do not have a schematic together yet for this point to point wiring. Sometime the schematic will be needed...