The integration of ESP8266 in the Arduino IDE offer a huge number of new opportunities. Below I will present a few fundamentals and projects, I've realized with this option
Simply follow the instruction on https://github.com/esp8266/Arduino
http://arduino.esp8266.com/stable/package_esp8266com_index.json into Additional Board Manager URLs field. You can add multiple URLs, separating them with commas.In order to start into programing mode, you need to press pull-down RESET as well as GPIO0 and allow RESET to become back Logic High while GPIO0 stays a bit longer at LOW. Once GPIO0 is back HIGH, the ESP8266 is expecting the program code.
I've built a progaming board for ESP-01 connector and modified for Arduino, so Iwithout need for buttons it will start automatically into pograming mode. This has been done by using DTR signal, triggering a small ATTiny25/45/85 which controls the levels at RESET and GPIO0. First I wanted to realized by discrete built Monoflop BUT DTR toggles several time Low-High-Low on power up. If you accept to do an additional Reset after power up, you can used that kind of solution as well.